Just a quick note that the amazing Dr. Petter has released an alpha version of sculptris, an awesome freeware 3D sculpting tool. I used it to make this nifty old man face in about 5 minutes, just playing around with the default settings and brush, and just using my mouse. Cool stuff!
Dr. Petter is also responsible for the sfxr, a free tool that helps you instantly generate 8-bit-ish sound effects (all of the sound effects in Crosstown and Spelunky were made with the sfxr), and musagi, a robust and very easy-to-learn free sequencer for making chiptune music.