A year into the its life span, if you're still not convinced that the Kinect is going to be a major part of our lives in the near future, you must be on something. Maybe I'll restate that. If you don't think affordable depth sensing technology will be an integral part in the way humans interact with machines, you must be on something. The amount of practical time and money saving hacks that have come out within the last year have ranged from inspirational to mind blowing.
I came across this easy to set up mouse control Kinect hack for Ubuntu. From what I can tell, you can't execute any "click" commands so it isn't the most practical hack out there. It may however prove to be a good jumping off point if you were interested in developing a Minority Report type interface for Ubuntu.
libfreenect is the end result of the famous Adafruit Kinect hacking bounty X-Prize winner. After it made its mark on the scene, the OpenKinect community was born and the rest is history. This guide will provide the resources necessary to install the OpenKinect libfreenect drivers for Ubuntu. The original installation guide can be found at OpenKinect's Getting Started Guide.