There is no capture software to my knowledge beside the static screen capture using home+sleep button.
As an alternative, if this is an iPad 2, you could mirror your screen to a tv output and capture that output with a computer having a tv input card. Could it be done with an hdmi connection? Maybe someone knows...
One thing I did to capture the screen was to create a black box in which you put your iPad with a webcam at the top to capture the display. The black box (just an ordinary box with a hole for your hands) will help get a better capture, avoiding reflection from lamps, or any other source of direct light. By adjusting the brightness and contrast, you'll get a pretty sharp capture and you can also see the hands/fingers interacting with the app.
Seeing the gestures from the hands makes it easier to understand how to pinch, rotate, select, etc...
My 2 cents...
VicoPad addict!