The very lovely Keri (aka mamatopooperjack) has asked for a list of baby gear and whether I recommend new, used, or borrowed, as she herself is the lucky mama of a toddler and she's expecting twins. This is not meant to be a comprehensive collection of things you need for twins. I am writing this as and for someone who already has one small child when the blessed multiples arrive -- someone who knows what a "sleep sack" is and has already realized that, while it may be adorable, your baby doesn't really need his own bathrobe. I suggest checking out the "Beginners Tips, Twin Must-Haves, & Hospital Bag List" post on Twinstuff.com for a more detailed list. And of course this is only my opinion, which is often completely wrong anyway, so I'm not even sure you should be reading this at all. Proceed at your own risk.
Car seats - new. I am weird about car seats... or maybe just lazy. Instead of trying to figure out if a used car seat is safe, I'd rather purchase a new one from a reputable brand and not worry about it. I just dropped $150 on a third Britax Roundabout because all the boys will be in those soon, but I think it's worth it. (We got the other two at our showers, thank you generous family members!) However, I did break this new-only rule with one of our infant car seats. My wonderful friend Kim gave us a Graco SnugRide that her nephew had outgrown. It was purchased around the same time we were getting the SnugRide for Bean back in late 2007 -- the fabrics coordinate with each other, in fact -- and I trusted her that it had never been in an accident. Coming from a friend, we gratefully accepted it (thanks again Kim!), and the twins currently ride around town in both recycled SnugRides. Otherwise, I personally would have purchased another new one instead of buying used from someone I don't know.
Stroller - used. The majority of mamas will be pushing their twinfants in a double frame snap 'n go stroller. There are other strollers that accommodate two infant seats, but to be honest I have no idea which ones. I suggest getting this item used, since you only need it for the early months anyway. Then you can resell it again if it's still in good condition. As far as post-infancy double strollers, see my stroller posts: one and two.
Crib - used. Imagine this: it's noon and you have two exhausted 6-month-olds and a ravenous toddler (growth spurt!). Unless you are Magical Queen of the Tandem Babywearing Mamas, you can't simultaneously sooth the infants to sleep while making a grilled cheese sandwich. You'll probably nurse the younger two and if they are still awake after that, you'll need to set them in their cribs to attend to the toddler's needs. You won't need two cribs the first day, or even the first month -- but you will soon enough. Many mamas have their twins share a crib for a while, but one of our twins is so active that he would constantly disturb his brother. We actually now have them in separate rooms completely so they won't wake each other. When you buy a used crib, you have a similar challenge as with car seats to ensure it is safe, except for one key point: cribs are much less likely to have been in auto accidents. I would steer clear of all drop-side cribs due to the massive recall, and with any crib, contact the manufacturer before making a purchase to make sure that your model has not been recalled.
Co-sleeper - borrow. I was lucky enough to have a friend offer her Arm's Reach Co-sleeper to use when the twins were first born. They slept cozy and swaddled next to each other beside our bed, which made nursing more convenient at night. Having double the weight, they outgrew it twice as fast, of course. If you decide to use one, free is the way to go, if possible.
High chair - new. This, of course, is only if you like high chairs in the first place. Many mamas aren't, they opt to go right into the booster seat instead. Already having a kiddo, you know whether you are a HCP (High Chair Person) or not. Personally, I am, and the thought of getting a used high chair with some unknown kid's food crusted all over it just grosses me out. So new it is!
Baby monitor - borrow. You may have seen our baby monitor farm in a previous post. It just kinda evolved. We are blessed in the fact that Bean does not get out of his bed on his own when he wakes up, even though he is physically able. But the way our house is laid out, we still need a monitor to hear him call for us. Then we have the twins in their respective cribs: Nix in the nursery, and Gax in our bedroom. We tried to go without additional monitors for weeks, but it wasn't working for us at all. One of my friends offered her old monitor, which is much appreciated. Then I did end up going to Walfarts and getting a cheap one for $14. Hopefully you won't need three like we do, but if you do, perhaps a friend or family member has one they are not using. (Or if you are feeling high-tech like Jen, you can purchase a video monitor with multiple transmitters. I'm just not that cool.)
Changing table - used. With three kiddos in diapers, one of the best decisions we made was to have multiple changing stations around the house. We have two upstairs (one on our dresser for nighttime changes, and one on Bean's dresser), and a friend graciously offered her changing table to put in our playroom. You could be depressed about the number of butts you'll wipe during the day, or you can just embrace it.
Diaper bag - new. I read a lot of reviews on various web sites before choosing the one I did. It's not particularly cute, but with three small children, it's function over form at this point. (This is the same reason I drive a minivan.) This diaper bag is industrial-sized and matches everything, including a manly husband. Done.
Nursing pillows - new. Definitely get a twin nursing pillow for tandem breastfeeding your newborns. I didn't use mine all that long for the purpose of tandem feeding, but now it helps to have pillows scattered throughout the house. Again, you already know if you are a Boppy Mama, and I definitely am. (I used ours a ton all the way up until Bean weaned at 18 months.) So I have the old Boppy in the twins' room by the glider-rocker, a new Boppy downstairs by a second glider-rocker, and the twin nursing pillow next to my bed for night feeding them separately. I'm already hauling babies all around the house, I don't need to haul a bunch of junk with me too. I'm a broken record: convenience is the key to survival.
Glider-rocker - used. I've heard a few mamas say they never use their glider-rocker, and I don't know your personal feeling, but I am completely in love with mine. We bought a really nice one when Bean was born and I have absolutely no regrets. Right now it's in the family room, where I nurse most of the time. But I am doing so much feeding both upstairs and down, we wanted an extra one for the nursery. (Me, for the convenience -- and DH because then I'll be less likely to wake him at night while breastfeeding in bed.) I would have loved to get a fancy one, but dropping another $500+ bucks was not an option, so we spent a much smaller sum on Craigslist. I can tell that it's not top-of-the-line when I'm in it, but it looks nice and does the job just fine.
Clothes - new & used. Because the twins are both fountains of spit-up where Bean was not, we definitely need at least twice the clothes. They have more wardrobe changes in a day than Lady Gaga, and I have to do laundry every other day. (The suggestion of putting them in bibs to protect clothing would be helpful if their puke didn't projectile past any futile attempts to keep their outfits clean.) We got a lot of donations from friends, which was awesome, and there's a nice resale shop near our house. Of course we do buy some new, because it's not hard to find inexpensive new baby clothes these days. Besides, you'll want some cute matchy-matchy stuff, too. Even if you swear you won't... you will.
Swing/jumperoo/Bumbo/bouncy seat/exersaucer - used, if needed. You probably already have a collection of these "activity/entertainment" items collecting dust in your garage or closet. And you probably won't need any more than you have, despite there being two infants this time around. If your twins are anything like mine, they don't like the same things AT. ALL. Nix loves laying on the mat and trying to pull the hanging toys into his mouth. Gax spends hours in the jumperoo building thigh muscles of steel. If both of your kiddos like the same thing, you can rotate them, or decide down the line to buy another one from Craigslist. What I would recommend, though, is having these type of items scattered throughout your house for -- say it with me! -- convenience. We have a swing in our bathroom for when I'm getting ready in the morning and need to stash a babe, and a bouncy seat that floats around the second floor as needed. And of course, something by the kitchen table so you can eat your (already cold) meal as quickly as possible.
Baby carrier - used. Okay, you knew this was coming. I do plan on writing a whole post on baby carriers, because (if it's even possible) I am more obsessed with them now than when I just had Bean. So for now, I'll keep it simple: get a Moby Wrap. You won't be using it long because it's too stretchy for a heavy baby, so if you don't already have one, find one at a resale shop, or Craigslist, or borrow/buy from a friend. Soon you will have more babies than you can shake a stick at, and it's helpful to wrap one up every now and then. I hate to use the term "hands free," because your hands will be full even when you are babywearing. But every little bit helps.
Meals. I am not sure how I would eat if my Mom didn't live with us. I'm guessing I would be rocking the Cap'n Crunch several times a day. When the twins were newborns, a friend of mine offered to go shopping and make meals for us to store in our freezer (I paid the grocery bill). That was really helpful. Another busy friend said that she uses a make-and-take-dinner place to provide meals for her family, another option for you. Also, when I was on bedrest and then into the first weeks of the twins lives, my friends provided three months of dinners for us 2-3 times a week, coordinated through the Lotsa Helping Hands web site. What a blessing! Whatever you do, remember you'll be constantly starving when you nurse twins, plus this time you'll have a toddler to think about after bringing home your babies, so you'll want some sort of plan in place -- even if it's gathering the menus of local restaurants that deliver.
And one of the most important things, which unfortunately you can't buy or borrow, is getting yourself mentally prepared for twins. It's time to adjust your expectations for yourself as a mother. Remember having one teeny tiny human with enormous needs, attached to you 24/7? Now you'll have two, plus a medium tiny human with constant needs as well. You won't -- no, you can't -- be the same mother to the twins that you were for your singleton. I like to think that there's a balance. Although I can't give of myself as much to the twins as I could to Bean, I am giving them each other. Yep, they'll thank me later. I'm pretty sure. Maybe. It's possible.
Good luck, and let me know if you have any questions on something I missed!