No damage can occur from plugging the Kinect in to your computer, but unless you have the necessary drivers installed, you won't be able to do much.
Please visit [http://openni.org/|OpenNI] for information about an open source Kinect platform.
The book [http://shop.oreilly.com/product/0636920020684.do|Making Things See] is a very good resource for getting started with hacking the Kinect.
I personally have been able to write a few small programs to use the functionality of the Kinect to perform other tasks on the computer.