i have the ultimate solution...
RED BULL...
IT GIVES YOU WINGS!!!!
but really, one of these and I'm active for the rest of the day.
If you don't want to do that, there are tons of great free games. Flash games, shockwave, freeware, ect. I guess the best place to look would be somewhere like newgrounds.com
whenever i'm overly bored, i go there. get a few laughs (lots of fart jokes, so there's my warning...)
thats what i do, and with luck it will help you!