One of the more amusing hacks in Smart Home Hacks is Building a Hamster-powered Nightlight. It's also a hack that I usually include in presentations because it's so much fun to describe, particularly with the way it ends. (A postscript that I add for the attendees.) But despite the inherent silliness, at its core it's a sound solution and clever application of engineering and problem solving.
For those who remained skeptical, I take great pleasure in referring you to Harnessing Hamster Power with a Nanogenerator as published in the MIT Technology Review.
Vindicated; at last.