The Mac OS X 10.4.7 update contained a pleasant surprise for MacBook Pro owners: Two-finger right-clicking is now an option. The feature can be enabled in the Keyboard & Mouse Preference Pane by checking Tap trackpad using two fingers for secondary click. The undocumented addition is good news for users that are slowed down by having to use the Control key when right-clicking, and for lefties since there is no Control key on the right side of the keyboard.
[Thanks to Hugh Gyetvai for pointing out the new feature.]