Let's get this straight: The iPad/iPhone-powered iDJ Live controller from Numark is likely not something any serious DJ would use. But the amateurs who have outgrown the DJ apps on their iOS devices might find some value in this controller, which uses the iOS app Djay.
Judging from the video, iDJ Live seems to work well enough for the curious novice to get their feet wet, but seems a bit too compact for anyone more ambitious. That said, it's $100 for the controller, and either $1 or $20 for the Djay app, depending on whether you get it for the iPhone or iPad. So if you get bored in a month, it's not a huge drain on your wallet. [Numark via Ubergizmo]