Ergonomic Resources: Browsing Whale Mouse <tinyurl.com> The Whale Mouse costs a hundred bucks (cheaper if you shop around) but it could be worth the money. It'll take the pressure off your arthritic knuckle joints. It functions just like a normal mouse but it's bigger and adjustable.

 
Contour Perfit Mouse Home Page - Because, One Size Doesn't Fit All <www.contourdesign.com> Another highly rated ergonomic mouse is the Perfit Mouse. Perfect fit, get it? It costs about ninety bucks--you won't find it at Walmart. ;-)

 
Ergonomic Products for the Workplace, plus Ergonomic Consulting Services and Training <www.askergoworks.com> Contour Mouse costs eighty bucks and comes in four sizes, either lefthanded or righthanded.

There are other ergonomic mice and mousepads and other stuff out there. For Windows, Linux or Mac. Do a Google websearch. Use keywords like arthritis, ergonomic and mouse.