We all know the importance of having a good mouse if you're working at your computer for long periods of time. But for gamers, its even more important to have a mouse with just the right layout of buttons, ergonomics, and speed. Logitech announced today the launch of their latest gaming mouse, the Logitech Optical Gaming Mouse G400. It doesn't look as cool as the Mad Catz Cyborg R.A.T. mouse we saw recently, but it's the successor to Logitech's MX518, which is their best-selling gaming mouse ever.