Logitech MX Revolution

Pros: Versatility, programmable per application, well-designed

Cons: Minor: Have to remember to recharge when not in use

Summary: As a graphic designer, constant movement and clicking leaves me with an acheing hand. This device is so far beyond anything I've used in that it provides a wide array of buttons all of which can be designated for specific actions within specific applications. Much less movement required, much more control. Especially helpful scrolling long documents, whether text or graphic.