Camcorder for use as a webcam
I know one solution, but it's not cheap as webcams. Same time full hd quality is something that webcams usually doesn't deliver.
Device especially interesting for live shows recording and streaming.

http://zoom.co.jp/products/q2hd

Webcam driver is provider by Zoom, so you still can use it as regular webcam delivering high quality video and audio to Skype for instance.

PS: there are plenty of reviews on youtube.