What are the options for manipulating video in live situation? Kinda like a VJ
The Max/MSP modular environment has a package called Jitter which is used for modifying videos in realtime. I've not had the chance to play with it myself, but I've seen it used in video art installations. Max supports several kinds of control such as MIDI and OSC, so I imagine all of these could be used to control video. 

You'll have to make your own patches though - it's not an 'out of the box' solution so much as a realtime programming environment.