André Michelle, inspired by the TENORI-ON, created a grid-sequencer called ToneMatrix. It's an interactive experience written in Flash 10 that merges graphics, visualization, interactivity, and music. There are also iPhone knock-offs such as the free TonePad. As for ToneMatrix, click here to check it out and create your own tunes. Here's one of mine.

Eine Kleine ToneMatrixMusik from S Woodside on Vimeo.

You can also right-click on the ToneMatrix flash app and copy/paste numerical sequences to load and save your music. The sequence for the above is:

98386,1024,4096,1024,67474,96,65540,32768,65618,1024,64,0,65618,4,65600,0

Share and enjoy.