Using @oliver's magical HoloBrush app in a prototype HoloPlayer, I've now drawn freehand this holographic "hello" in mid-air in glorious 3D probably 200+ times at Siggraph/demos at taco bars/family gatherings. It is now my technological act of meditation.
p.s. ok, yes, I admit it! I totally stole the font-style from the original "Hello 1" 1984 Mac ad.