Startrek had these things called holodecks, where holograms were kind of "real" and could interact with people physically:
http://en.wikipedia.org/wiki/Holodeck

I've often wished holograms were real, so they could watch my kids 24/7 while I slept! That probably reflects on me as a parent (in a bad way haha).

Would you take advantage of a holographic nanny?