Oblique Strategies as a Mac OS X app
Brian Eno's Oblique Strategies are a set of one-line instructions to be selected at random to break creative block or shake things up in the creative process.
Discard an axiom.
Find a safe part and use it as an anchor.
Reverse.
Shayne of curvedspace has now implemented an Oblique Strategies app for Mac OS X. (Via Ed Vielmetti.)
Geeks have been playing with the Oblique Strategies for a long time. Here's a Usenet thread from 1992. Someone even implemented them in FORTRAN!
The strategies invite many variations. This gets the gears in my head turning about a version suitable for children.