hmm... I just received an invite to try APB for free for a five days. It might be worth to check it out... if my system is up to the task, of course. I will need to check the requirements first.
 
EDIT: is an Athlon64 X2 4400+ w/ 4GB memory and a GF8800 w/ 640MB good enough? I can still play most other games at a good level of detail.