My son just turned two months old yesterday…
Things I appreciated the most/least:
—people who purchased off the registry are wonderful! Please, please, please do this! Trust me, your friend/relative does not need another handmade blanket (not that they aren’t nice). If you want to get something personal (not on the registry), you should accompany the gift with something (at least small) that does come from the registry. Seriously, do this. It will be appreciated.
—If you do purchase an item not off the registry, and it is clothing, it is best to buy something for when the baby is older. As @meiosis mentioned, your friend will get a TON of newborn and 0–3 month clothing. Seriously, I had so much he didn’t even wear half of it. (He was 10 lbs when born so never wore his newborn stuff and was out of 0–3 this week, at 2 months old). Something in 3–6 or 6–9 (or older) is better.
—I personally LOVE slipper socks like this:
http://www.gymboree.com/shop/dept_item.jsp?PRODUCT%3C%3Eprd_id=845524445994281&FOLDER%3C%3Efolder_id=2534374306255789&ASSORTMENT%3C%3East_id=1408474395917465&bmUID=1286970032236
—I agree with diapers and wipes. You can never have enough of them, particularly size 2 or 3. Your friend will most likely be prepared for when the baby first comes home (size 1).
—Gift cards for food and casseroles are also nice. My sister, best friend and family all brought us dinner and/or casseroles to put in the freezer. This was really nice. Dominoes gift cards would also come in handy.