It's getting hot and you desperately need a little fan to fit onto your desk. You could either go buy one or you could finally do something with that old PC of yours and tear out its power supply fan.
Apparently some fellow discovered that the quickest way to "make" a fan is to take out an old computer's power supply fan, rip out all "unnecessary bits and pieces," leave the power adapter inside, and tada! A little fan for your desk. [Guus Oosterbaan via Unplggd]
Whoops! Let's account for human stupidity and add a disclaimer: Don't try this project if you have no experience fiddling with power supplies or don't really truly know what you're doing. There's potential for you to get injured...or killed. It's not a good idea to follow vague instructions that tell you to toss out "unnecessary bits and pieces." #badideas