Meanwhile, there is Gowalla. I've tried to use Gowalla for a while. None of my friends are using it. I try really hard to use it, yet I can't seem to understand their gaming rules. Stamps are everywhere, occasionaly I got items that I can add to Collection (but I have no idea what it really does) and so far I got no special rewards nor tips that caught my attention. So far, Gowalla is pretty much useless. The graphic has always been really nice (their latest update makes it even more), the receipt-printing animation is very slick, the stamps and items are very nicely designed - but in the end I just cant find their value proposition. Try harder guys!