video in / capture ?

Is there any easy way to add a "video in" to the Mini ?  That is, so via
software the screen could switch to show a backup camera, or video from a
DVD/iPod ?

In lieu of this, do you think there is enough horsepower to use a USB video
capture, and then merge the video in with the standard LCD output path (so
that the video could be windowed on the monitor - half screen, etc.)

Thanks