So here's something you probably didn't know: If you're ever in a pinch for a microphone, to record something quickly when the quality doesn't really matter, you can always use a pair of headphones. Say WHAT? Yep, it's true! A microphone is the same as a speaker. The diaphragm of the driver of the headphones is moved by the molecules of air that make up a soundwave. This driver is attached to a coil of wire (voice coil) which rests between a magnet. As the coil moves through the magnetic field, a current is produced.
So how do you do it?
Simple! Just get a pair of headphones and plug them into your laptop's input. Or plug them into whatever recording device you're using. Then hit record and start talking into the earpiece.
It seems to work best with cheaper iPod type headphones. And it doesn't always work. Sometimes it depends whether the mic jack supplies voltage and whether that voltage is as limited as it should be. But give it a try! You have nothing to lose.