XP could slow your system...
Windows XP SP1 glitch could slow systems
Because of changes made in SP1 to Windows XP's memory management system, programs that affect large blocks of memory may take up to ten times longer to load on a system running SP1 than on one without, Microsoft said. The company detailed the problem on its support Web site in a recently posted Knowledge Base article, "Programs Run Slower After You Install Windows XP SP-1" (article #815411). [InfoWorld] 

Product Review: Logitech Mouseman Dual Optical...
My sister and I are both using the Logitech MouseMan Dual Optical mouse and I must say, what a mouse. The MouseMan Dual features the "standard" 3button/wheel mouse configuration as well as toting an additional programmable side button and an innovative ergonomic design. The general shape of the mouse is slightly curved with a higher arc to the middle making for a comfortable fit. Perfect for people like me who make their living point-and-clicking all day. It's a definite must have for the office. Check it out here