Baggagelizard on Youtube put together a makeshift projection system (his laptop and a piece of glass) to make Aiko dance!
It’s not quite the same tech that the Vocaloid concerts have used, but it’s similar and works at any scale… making semi-low-budget UTAU live concerts a possibility in the future, perhaps? ;D
EDIT: I tried my hand at the technique. Mine’s a lot grainier due to a low-quality camera, but here’s Aiko and Namida dancing on my own desk xD