nthCaller allows you to run 'caller number --' contests from your
Just pick a number and the winning call will be transferred to your phone.
Currently in beta, so you'll need a contest code to play around with
But that's pretty easy to get. Just tweet your request to @nthcaller - and it wouldn't hurt to mention what amazing things you're going to use it for.
Speaking of amazing things, if you work at a radio station you probably already know what you can use this for. But it's also a great way to raffle off a prize at conferences, decide who gets to pick your group's weekend destination, connect one lucky fan to their favorite celebrity, or even - well, I'm sure you already know what you're going to use it for.