We use cloth diapers. But occasionally when we leave town for more than a couple of days and won't have laundry facilities we have to use disposables (and if I can, I take them home to our green bin to avoid landfilling them). When we do, I usually just go and buy the no name type (the name brands are just too perfumey for me). But we have a trip coming up and now that I'm in green mode I can't help but look into the issues with everything (and my mom just bought me Ecoholic as an early birthday present - great book).
With disposable diapers, it's mostly the problem of landfill (5000-7000 diapers per child - about 1.8 billion diapers per year in Canada alone). The other problems include (from the Green Guide) the fact that most are bleached, which contributes to the creation of dioxin (very, very toxic); the fact that most people don't flush the poop before they landfill the diapers, so landfills are being filled with raw sewage, which they're not equipped to deal with and can result in groundwater contamination; and a possible link to asthma. They also contain perfumes and plastics (the absorbent gel).
So, when we have to use disposables, from now on they'll be Tushies which are chemical-free, fragrance-free, chlorine-free, and gel-free.
~ Lynn