I had the same idea last year (note date! definitely a springtime thing):
http://www.able2know.com/forums/viewtopic.php?t=49801
The only thing that's really worked, for me, is to join a gym. :-?
I did see an absolutely awesome commercial recently, with the same basic idea as shewolf... it's part of some public service/ health initiative but I forget what it's called (I'm sure it has a website).
Anyway, it's winter, snowy, and there are some garbagemen out early-early, while it's still dark. It's a tiny bit scary/ ominous, half expecting aliens to beam down or something. Suddenly a close-up of one of the garbage guys -- "Hey, what's that?" They slow down, the garbage guy leaves the truck and inspects something (out of the frame) and then leans in to grab it; his face is neutral, we don't know what we're going to see. He pulls up into the frame some amorphous blob. He looks off into the middle distance and you see a few snowmen in someone's yard. Camera goes back to the object -- it's a jiggly large tube of some sort. Garbage guy shouts back to his friend, "It's someone's thunder thighs. Must've lost 'em when they were playing in the snow with their kids," and goes on his way.
It's a good series, another one is a person parking way at the back of the parking lot, even though there are lots of spaces open, and as she walks towards the store gathering a cheering crowd... etc.