...I talk on the phone and maintain the game quality? Can I use Voip service playing ps2 online and talking on the phone at the same time and maintain the quality of my game?I have a wireless router and an adapter.

It shouldn't cause problems as long as you have a fast enough connection - I have 10Meg broadband (512K upload) and a 802.11g wireless router, and I can do several bandwidth intensive things at once without problems.