In less than one hour in GMT (11pm) the official trailer for GTA 4 will play at
http://www.rockstargames.com/IV/
You all need to know this, and if you have to ask me why, you probably live under a rock. Rockstar have promised that the trailer will be so much more than a mere teaser, and will give fans a real look at what the game is going to be like.
Hopefully it will settle the debate as to what location the game is set in.
Go there now and you might avoid the queues. No one is entirely sure what kind of servers Rockstar have set up for this, so there may or may not be a horrible bandwidth shortage when thousands upon thousands of people try to view it all at the same time.
Why are you still reading this? It should be pretty clear what you need to be doing right now.