for Mac OS X Users
Did you know that you can use most USB two-button mice with Mac OS X? You can and you don't even need to install drivers to do it. Just plug that USB mouse into an available USB port and OS X will automatically detect it giving you Control-click functionality with right button. Not only that, but Mac OS X can also make use of scroll-wheel mice as well. All that with no extra software needed. Just be sure to try before you buy.
If you want to use one of the fancier three-or-more-button mice, you will need extra software to make use of all the extra buttons.
If the mouse you want doesn't come with Mac drivers, there's a good chance that USB Overdrive from Alessandro Levi Montalcini will make it work. USB Overdrive costs $20 and works with any USB mouse, trackball, joystick, or gamepad device.
So check out the world of multi-button mice and give that overworked Control key a well-deserved rest.