Is it possible to map the tab button onto a Mighty Mouse? I would like to use my extra button on my mouse to provide the same function as the tab key does on my keyboard. Is this possible? If so what must I do to make this work?
You should be able to, yes. You can map AppleScripts to mouse buttons, so you could write a simple AppleScript that sends the tab character. I'm not that familiar with AppleScript, but you should be able to find the info you need on Google.