I’ve just found a hilarious list of self defence gadgets from cracked.com. Here’s one of my favorites:

#6.Romatron Personal Protection Keychain

Grab your keys and hit yourself in the face with them. Hurts, doesn’t it? That is the awesome might of The Romatron. But wait, The Romatron comes with a Polymer Ball on a Steel Cable! Doesn’t seem like much? Here’s an excerpt from the FAQ:

“Won’t using this against an attacker just make him mad?”
“No, hitting someone with a romatron will disable him, just as if you hit them with a baseball bat.”

They also boast that, “Romatron is taught as part of Kuden Jutsu, a martial art recognized by the World Karate Organization,” and we believe them. Jackie Chan could probably take out a whole bar full of guys armed with nothing but this thing. But let’s face it, once you’ve grown bad-ass enough that you can take out a guy with your car keys and a rubber chew toy, you can pretty much use whatever happens to be laying around and don’t need to make a special purchase.