Haven't cleaned your desk in years? At this point you've probably accumulated enough crap to recycle it all into something useful, instead of just sweeping it all onto the floor. YouTube's MrGear has an easy-to-follow tutorial show you how to turn an old CD case, some soda cans, and various unwanted electronic bits into a working homebrew blower.
The results are, well, ugly, compared to hair dryers you can buy at a store. And MrGear hasn't included a heater in his creation, mostly because it's held together with mountains of glue that would melt causing the blower to fall apart in just a few minutes. So it's not exactly the ideal way to dry your hair after a morning shower. But hey, at least your desk will be a little cleaner, right?