Have yet another backlog of sites. The "Time":http://www.time.com/time/specials/2007/article/1,28804,1809858_1809957,00.html list is pretty good:
GasBuddy has real time prices from the community. Save a few bucks!
TripKick since TripAdvisor isn't good enough. It tells you which floor to stay on 🙂
AfriGadget are simple things that can work in the developing world
PopSugar shows I'm a bad person. I love reading gossip!
Picnik uses flash so you can do basic picture editing. I don't think I'd actually use it, but amazing user interface and the future of applications imho.
http://www.noslang.com/ is the way to figure out all the slang being used on the internet. For instance l33tspeak which means you replace letters with numbers like she1b0y. Lots of things I didn't know like P911 or W/E (my current favorite!).