Make Miku Dance

JohnSu has created a simple (and cute!) Miku dancing program in Flash, that lets you control the little character's basic body movement – sway – by mouse movement. There are several backgrounds you can pick, lip-sync – it doesn't have any sound itself, so that needs to be run separately – you can set key binding for the other controls, and it's all simple, happy fun.

Here's a short video to show what can be done with Halfne Miku Studio, as he has called the program. I do like the giant leeks turned inward to form a kind of arch effect.

UPDATE: There are now dozens of examples of this program's use here. This one (below) is still the original demo, though...