Avoiding carpal tunnel / repetitive stress injuries
elai: For me, I was starting to get wrist pain with my mousing.  I purchased 12 different mice, tried them all out, keeping note of how I felt in my hand.  I eventually found out that really large mice is what work for me.  The M$ intellimouse explorer specifically.  The MX revolution, and all the other fancy mice weren't as good as the huge honking intellimouse explorer. The huge thumball mice were also good, but I didn't have the patience to learn them.