Failing the J&J stuff (which I tried to find today, but it's sold out like, everywhere!) I've heard St Tropez is really good.
I like the gradual tanning idea though, so I made my own tanning moisturiser. People on the vogue forums recommend Face of Australia as a cheap but effective product, so I used that and some random moisturiser in priceline (3 parts moisturiser, 1 part tanner). The tan was a foam, but I put it in anyway and mixed it really well... provided it works, all will be well!
EDIT: I'd rather get my tan out of a bottle... most studies show that it's safer than being in the sun
Although like most things, I guess moderation is the key? *has no idea*