After a gig on the weekend using DVD player, iPhoto and iTunes I was wondering if an app existed to fade between all of them in a live performance situation.

I was using a PB 17′ with a digital video projector. Thought it would be the ultimate app for an all in one mobile solution. The ideal would be to use the projector as my main show screen and the laptop as my workspace. Obviously one can do this already. But to negate the need for a video mixer, it would be great to be able to fade between Apple DVD player, iPhoto, and iTunes (and other apps of this kind). An app that was a mini audio and video mixer all in one. Does it already exist?