What are some unusual uses of the MacBook trackpad?

You know, the MacBook has such a beautiful trackpad. Are there applications that use its power for music-making, drawing, or anything else unusual?

Solution 1:

In the "unusual" camp there's a program called Inklet that purports to turn your trackpad into a Wacom-like tablet. They also sell a special stylus and sketching software.

For music there's Trackpad Magic, which allows you to create music using trackpad for input, and djay, a DJ'ing app that lets you "scratch" records with your trackpad.

Solution 2:

There is MultiTouchMIDI by Jeff Kaufman, a free software that translate pressure on the trackpad into MIDI signal.

You can then use a music software to translate this MIDI into audio.

It is then a good Idea to have an external mouse that can control the pointer. Check "Ignore Trackpad when Mouse is plugged in" under Universal Access, so the mouse holds still when you play music.