If you've got an old desktop PC that's just waiting to be retired to the computer graveyard, here's an inventive project that will put at least one part of it to good use again: PC fans repurposed as mini wind-powered turbines.
The Scrap to Power blog has put together step-by-step photo instructions on how to recycle those CPU tower cooling fans by transforming them into mini wind power generators that can recharge solar lights and rechargeable batteries. These little wind-powered motors can generate around 1.5 - 2V in an 8 mph wind.
Besides the soldering iron (which you can get at Radio Shack for less than 10 bucks), the rest of the materials needed include items most of us have around our house or are things that can be easily found at any home improvement store.
Photo and information via Scrap to Power.