1. Take fat chicks home
2. Throw molotov cocktails in your path
3. Attempt to fly south
4. Let George Lopez heat you with his freaky eyes
5. Kidnap - it works up quite a sweat
I suppose you could just stick to bundling up, but I strongly advise against it; It's less fun, you look like a bitch, and makes you very susceptible to falling down hills.
Rape's another good one, but if you're ANY fun, that's included in "kidnapping" as well.