I have been playing a lot of GTA4 this week and I don't think I am going to complete it in under 30 hours (you get an achievement for that). But there are two awesome websites inside the game that I need to tell you about.
Goto an internet coffee and lookup:
www.bruiesexcutivelifestyleautos.com
www.whattheydonotwantyoutoknow.com
The second is a website detailing GTA4 secrets. This is a first, a website made by the game's developers detailing secrets about their own game, on a fake in-game internet. Which is funny because I always look at websites for cheats and secrets, but now I don't even have to leave the game to do that (yes I do know EVE Online has it's own built in web browser, but that is for the real internet, not a fake one).