SwingDJs

Not so much an issue when dj'ing, but I'm sure you've all heard your cell's familiar interference pattern when you have a call coming in. Anyhow, here's a neat little way to stop that.
http://www.maclife.com/article/iphone_buzz_kill

Hmm, yet another way to get rid of that buzz from your mp3 player for $5... http://www.quickbridgesolutions.com/