Fast Forward in QuickTime
You can fast forward or quickly rewind any video playing in QuickTime Player by using a trackpad or magic mouse. Simply drag two fingers horizontally across the touch surface, dragging to the right will fast forward, dragging to the left will fast reverse. The distance of your drag in either direction effects the speed of the playback, from minimal speed increase up to 8x fast forward mode.
This has been tested to work with QuickTime Player 10 in Mac OS X 10.6.5, the other requirement would likely be a multitouch supported tracking surface.