One of the best investments a heavy computer user can make is to purchase a good quality mouse, I am not here to sell a mouse, but here to discuss how to make it work better for you efficient

Increase efficiency = Increase your value as an employee

If anyone has a programmable mouse, say logitech MX revolution, you are able to program the short cuts into the mouse.  My favorite example is to program Ctrl+TAB and Shift+Ctrl+Tab into the mouse and I am able to quickly navigate between Tabs in Firefox just by using the mouse.  You can do this for a lot of programs, with just a few minutes of set-up, you can save tons of time and navigate multiple pages faster than ever.

Excel
program Ctrl+page up and ctrl+page down to quickly move between pages in an open work book

Outlook
Ctrl+E will take you directly to the Instant Search bar
Ctrl+Shift+V will make it easier than ever to file messages

Mice are often over looked as productivity enhancers, but any edge you can give yourself will save you time and allow you to do more with less.  Or at least allow more time to read more Feeds and jump on Facebook