Hoho! yes! How to make reallistic human movements in Silverlight? 

Check out this stickman animation demo here: http://www.nokola.com/mocap.html

Download source code for the above sample in the attachments to this post below.

You're looking at 3D realtime animation of stick man figures using motion data found on the internet.

The motion capture viewer took me the whole day yesterday - still nothing compared to doing these animations manually frame by frame.

As a start, you need movement data (motion capture or mocap data). You can find a lot of that online. This site http://sites.google.com/a/cgspeed.com/cgspeed/motion-capture/3dsmax-friendly-release-of-cmu-motion-database contains thousands of human motions - e.g. jump, punch, kick, wash windows, mop floor, and other.

I used the .BVH files - they have a short description of the skeleton being animated (joints, head etc) as well as rotational information (e.g. "wrist should be rotated at 50 degrees at time X")

Since this is a work in progress, I'm just publishing this quick blog post - more info will come later, because I want to make the animations transition into each other.

In the future I'll talk about the motion capture file formats and some challenges I faced (and are still facing!) implementing the above sample.

Here's a quick overview of motion capture from Wikipedia: 

"Motion capture, motion tracking, or mocap are terms used to describe the process of recording movement and translating that movement onto a digital model. Initially invented in Scotland, it is used in military, entertainment, sports, and medical applications. In filmmaking it refers to recording actions of human actors, and using that information to animate digital character models in 3D animation. When it includes face, fingers and captures subtle expressions, it is often referred to as performance capture."

http://en.wikipedia.org/wiki/Motion_capture

Motion capture is used in games, movie special effects, and now in demos like the one above :)