I'd never heard of 'Hatsune Miku' before (a Japanese animated character who looks like a 16-year-old girl with long, turquoise hair). She is a music sensation in the Far East and has sell-out concerts all over the place. Apparently, they project her image onto a stage set like a hologram. Her voice is a computer synthesized sampling of a real person named Saki Fujita.
The effects pedal maps that vocalizing effect to your guitar producing hilarious results. I fell about laughing whilst playing with this!
Although I don't think I'd ever buy one, the novelty would surely wear off fairly quickly, I did start to wonder what guitar effect pedals everyone else enjoys. Do you have a favorite?