This is a nifty little application which is written in the Processing language, which allows you to draw stick figures and export them to Blender for animation.

http://screamyguy.net/sketchBoard/index.htm

If you haven't heard of Processing, it's an open source programming language and environment for people who want to program images, animation, and interactions. You can check it out at: http://processing.org/

Processing can be exported to Java Applets which can be embeded into web pages, such as the first sketch board link above.