Video Delay Lines

most video delay lines are just passive filters that provide very short (usually nano seconds) delay times to correct signals between sources over long cables runs and other related problems. However there are other ways to achieve real video delays for video installations and the like. I have a Korg Entrancer which does 6 seconds of delay, some DVD recorders have functions that allow them to output a delayed signal and there are commercially available studio units used for broadcast delays on live TV. There is also this, while still expensive its small form factor could be an advantage for cramped installations or live stuff.