Here are my suggestions, in point form!
-Go out and punch the rain until you scare it away.
-Go to the local pub, talk to women.
-Call up a friend, then build the bike generator thing and make them power your computer while you game.
-Play solitare until you win 20 times in a row without fixing the deck or cheating, this task should kill the time far before you complete it, or it could drive you batshit insane.
-Make a death ray out of your microwave, go over to a friend's house and kill his or her small rodential pet or fish with it to show them how it works.
-Challenge yourself to see how wet you can get your face before wiping it off by running fast in the rain.
-Do all of the above within the time your power is out, then proclaim yourself champion of the world.
Now go forth to victory!