A few months ago, on 28 November 2012, the vocaloid named IA (taken from her voice provider's name, Lia) had her first live concert, with a rather small audience. Her 'sub-name' (for want of a better term) is Aria on the Planetes.
Other performers were featured at this event as well, but the following eleven-minute clip is of just her three songs: Children's Record, Headphone Actor, and World Calling. Sadly the subtitles are in Japanese and Chinese only, but the performance is very good, I think, and merits watching at least the first song.
The lady's very good live, with her own vocal and visual style and stage presence. Her second outfit is really quite sweet, and it's worth sticking with this: trust me!
Overall, I was impressed with this effort, and am pleased that more vocaloids are appearing on stage nowadays.
Oh, and I don't think that was really Darth Vader on the dark side of the stage, on guitar...