Collaborative Music Jamming
The jam2jam activity allows users to make music on the laptop.
Music is generated by jam2jam and by dragging around instrument icons you can change the music as you like.
jam2jam was developed by the Australasian CRC for Interaction Design
See jam2jam.com for an idea of where this is going! The current longer-standing version has been developed for the Mac (with video background, live or stored, photoreel backgrounds, and various export formats).
The jam2jam xo activity for the OLPC computer can be downloaded here.