Sam Welker takes a look at using the Xbox Kinect and NI-Mate to grab motion capture data and use that in Cinema 4D to drive animated objects. NI-Mate is
freely distributed real-time motion capture & sound control for kinect
that is available for windows and os x.

Code monkey and general enthusiast Charles Rowland (@ragingClaw) also provides some great resources for free motion capture data:

CMU Graphics Lab Motion Capture Database
Free Motion Capture
MoCap Data

Check out the tutorial for Creating Motion Capture for Cinema 4D using the Kinect here.

Sam Welker writes: In this tutorial I go over the basics of how my scenes worked. I will create another tutorial soon going over the usage of NI-mate (and maybe iPisoft).

find these tools here:
ni-mate.com/
ipisoft.com/

Also make sure to make cool stuff!
More can be found on blog.thinkparticle.com