Speaking of jet engines, I recently saw something on the web about an inventor dude who built a minature jet turbine, so he could have a jet-powered beer cooler. If I can find the link again, I'll post it here.
Evidently the tiny jet somehow cooled the beer from warm room temp to near-freezing in about, oh, 3 SECONDS or so. It was pretty wild. He even had a .wav file of the thing starting up, it was deafeningly loud (think airshow loud!) Now that's an invention I fully support.
EDIT: found the link.
http://asciimation.co.nz/beer/