Textmouse is a program in development that is supposed to help with mouse-related RSI by converting Web pages to numbers that you can press on your keyboard’s number pad, thus eliminating the need to point and click with the mouse. “The TextMouse Web Executive – RSI Web browser utilizes a keyboard-based paradigm that makes use of the mouse optional in most circumstances, and enables web browsing via the number pad, or via a combination of alphabetic characters and the number pad. The keyboard-based paradigm is not based upon cryptic keyboard shortcuts like those found in mainstream web browsers.”
Although I like the idea of lessening the work you do with your hands, I’m not sure swapping out extra mouse clicking for extra keyboard tapping is really an effective answer. Personally, I’d recommend voice recognition software or an ergonomic mouse (if you can get a hold of an iGesture, they’re great, or maybe try one of the joystick shaped mice where the clicking is done with the thumb–a stronger digit that can handle more abuse), but if you want to try TextMouse, it looks like you can download it for free on their site (for now anyway). It’s hard to beat free.