The presentation I gave at Seattle Ignite 9, shot from a phone so the quality isn't the best (but quite good considering)
For renderings seen in the slides below (and site), I used AC3D (commercial CAD software that runs nicely on linux), and povray. The latter would have been much less fun without these excellent tutorials.
Source for the bits that tied together fragments of .pov files to create complete renderings and animations.
Slides attached below.