SideTrack is a replacement driver for the trackpad (touchpad) found on Apple PowerBooks and iBooks. It brings many of the advanced trackpad features found on Windows laptops to MacOS X.
SideTrack supports these features:
– Vertical scrolling at left or right edge of pad.
– Horizontal scrolling at top or bottom edge of pad.
– Map hardware button to left or right click.
– Map trackpad taps to no action, left click, left click drag (with or without drag lock), or right click.
– Compatible with uControl, including uControl’s scroll emulation.
– SideTrack is fully multiuser aware, different users on the same PowerBook can have different settings depending on their needs.
More info and download link here.