Custom sound track / song list allowable games on PS3?

[west-phoenix-az]

I don't have a PS3 yet so this may be a stupid question.

 

I assume you can't create a custom sound track (song list) for every game.

So what games allow you to load songs on your PS3 and play them in-game with in-game sound effects?

Is there any word if GTAIV will allow custom sound tracks?

Thanks,