The last talk I went to on day 3 of Linux.Conf.Au was Andrew Tridgel's "A tour of my junkcode directory". Essentially Tridge is advocating that we keep all of the little bits of code that we write when testing a bug, learning a library call, etc for later reuse. Our little bits of junk code can server as useful examples to jog your memory later, as he says "the best example code is your own". A few useful bits of junk code that he's made public are tserver, a tiny embedded web server, with basic bash CGI support. 3dttt, an OpenGL 3D Tic-Tac-Toe program. Tridge publishes some of his junk code here, and the slides of this talk are available here.