I've been trying out some software on Windows XP called Gentle Mouse; its function is to reduce mouse clicks. After the cursor stops moving, a menu pops up and lets the user choose different actions such as left-click/right-click/double-click. The user can then just move the cursor to the corresponding box and the action will be immediately performed.
This application greatly reduces my finger strain caused by mouse clicks. Unfortunately it is not free, so I really want to see if a freeware alternative exists.