If you are part of a mining pool, you will be credited by your hashing power contribution. I think if you could get a cheap asic miner and free electricity, it might be worth your while in the long run. As bfv says, it all depends upon just how much BTC is worth, and how quickly it appreciates.
kleinbl00, I don't think you'd turn a profit on anything but a free mining rig within 5 weeks. But I read about some brothers trying to sell water heaters that were heated by bitcoin miners.
I think it'd be cool to get a raspberry pi and make a solar, wind, or tidal mining rig.