Hey, I just saw some things called Stirling engines on the interwebs, but I don't understand how they work. Can anyone talk about em here?
GIYF. I can't explain 'em very well, but I might try
or How Stirling Engines Work | HowStuffWorks
Check around, there are very nice looking working models available.
Have a look around this site.
These guys build all that sort of stuff. Check out Steve Huck's little demon V8 engine, and gbritnell's amazing models .... too cool
Hi, I bought a model Stirling engine off ebay, sits on a hot cup of coffee and runs beautifully.
I did a thermodynamics prac at uni many many years ago, on the efficiency of a Stirling engine, it was a magificent brass machine built for laboratory use with 30cm flywheel and 10 or 15cm stroke, over 100years old.
Tom.... 
Awesome! We just bought one to replace the one that was lost. Very nice! I'll read more about it. Maybe it can be something for doomsday, since it runs on any heat source, unlike gasoline or diesel engines.