This six foot tall holographic display system is large enough to display people at pretty close to life size. It could be your big screen holographic TV and your first holographic phone system, all in one.
With a 70" diagonal display, Holocube's holographic projection booth is capable of displaying full-size three-dimensional people, as long as they're fairly short. The display is transparent at the back so that you can walk around it and get the whole 3D effect, and at full 1080p resolution, it's essentially like having some kind of real person standing there inside a box that they can't get out of, which is how I prefer all of my social interactions anyway.
At the moment, there's no equivalent system to capture and transmit holographic video in real time, so we're a couple steps away from a two-way holographic phone, and the Holocube just plays back pre-recorded video. In any case, it seems to be intended primarily for product display, catering to "fashionable generation X & Y shoppers" (whoever they are).
As far as cost, a 10" Holocube is nearly $10,000, so you can extrapolate from there what the 70" version will run you. It's a depressingly large number, but cheer up, at least the tech exists now, and sooner or later, we'll all be wondering what we did before it was possible to beam yourself into someone else's living room to talk to them.