I just checked out the new tribes game. It's supposed to be the fastest FPS in the history of ever. It's pretty fast and alotta fun. It's built on the Unreal engine, but has jetpacks for flight and aerial shootouts. You can also 'ski' which basically turns your guy frictionless, allowing you to slide over all the terrain.
I'm still working on figuring out the in-game communication/chat but if anybody wants to friend me, I'm peoplething......surprise, surprise.