Two things.
1. Search macosxhints.com. There's a terminal command on there somewhere that'll let you speed up the mouse as fast as you like.
2. "Unlike in Windows, the mouse pointer speed varies depending on how fast you move the mouse." Untrue. Windows supports this feature as well, and it's on by default in WindowsXP. It's the 'Enhance Pointer Precision' checkbox in the Mouse control panel applet.