Pandora's always seemed like a brilliant idea, but now that it's untethered from a computer, people are flocking to it droves, at the rate of a new user every 2 seconds. Recently released usage stats have put Pandora's free app, which allows users to listen to internet radio tailored to their tastes, fourth most popular, after Apple's Remote, Aim and Weatherbug.

The most shocking statistic is the average time spent on the program, with listeners averaging over an hour at a time. That's the kind of stat that makes advertisers drool, and sure enough, Pandora plans to monetize the service soon. Hopefully, their plan doesn't consist of adding the same sort of commercials that have made terrestrial radio so unappealing.