Listing every possible combination of a set
The problem is simple. Say you have a set of 12 elements. You want to find and to list every possible unique combination of those elements, irrespective of the ordering within each combination. The number of elements making up each combination can range between 1 and 12. Thanks to the demands of some university work, I've written a script that does just this (written in PHP). Whack it on your web server (or command-line), give it a spin, hack away at it, and use it to your heart's content.