ZeroFriction Infinity Mouse Skates.
They're teflon pads you stick on the mouse's "feet". Absolutely no drag. It actually took me an hour or so to get used to how responsive my optic mouse is.
I go with a Microsoft IntelliEye, the one with 2 extra buttons on the outside. Just makes web surfing soooo much easier, and if the game reads it, can help with a FPS as well. Always nice to have extra buttons.
What I'm hoping is that the new Playstation is able to handle a keyboard/mouse hookup so I can play FPS games on the console.