The Straight Dope has a hilarious anecdote describing the strange confluence of a remote-control blimp, central heating and the fight/flight instincts of homo sapiens.
A taste of what lies beyond that link:
The blimp which was up until this moment a fun toy here embarked on a career of evil. Using the artificial convection of my central heating, the blimp stealthily departed my office. It moved silently through the living and drifted to the staircase. Gliding wraithlike over the staircase it then entered the bedroom where my wife and I lay sleeping peacefully.
I bet you can see where this one is headed. Go and read the whole thing.