Propeller Powered Paxton Pinball
I thought this was pretty cool & and it's propeller-powered. Ben Heck (Who I heard of from ripping multiple video game systems apart and putting them in smaller cases) made his own pinball machine, with the theme of 'Bill Paxton'. It's all powered by a Propeller - he writes about starting out with a Basic Stamp, and moving on to a Prop here. It was pretty well covered by the media.
One thing I thought was interesting - he used 2 SD cards simulatenously because of the Fat16 limit. During the project, fsrw was upgraded to support fat32, but he wanted to stick with what he already had working.
Here's a photo of the finished machine;
and the full article. There's also a brief tutorial on Spin in there.