As of March 2011, there are two software possibilities to use the Microsoft Kinect:

OpenKinect/libfreenect: fully open source but still lacking some functionality
OpenNI framework + Prime Sensor drivers + NITE binaries for skeleton tracking and gesture recognition. The last component is closed source, while the first two ones are open source

OpenKinect/libfreenect

tbc

YARP wrapper

See $YARP_ROOT/src/modules/kinect/README.txt for installation instructions.

Installing binary files, if you prefer this possibility, is straightforward.

Below we explain how to manually install Kinect programs on Ubuntu 10.04 LTS (officially you need 10.10 or higher, but 10.04 works too).

The following instructions refer to the Unstable branch.

Mandatory:

 sudo apt-get install g++ python git-core libusb-1.0.0-dev freeglut3-dev
 audo adduser YOURNAME video

Optional:

 sudo apt-get install doxygen graphviz

 mkdir ~/kinect && cd ~/kinect
 git clone https://github.com/OpenNI/OpenNI.git
 cd OpenNI

 cd ~/kinect
 git clone https://github.com/boilerbots/Sensor.git
 cd Sensor
 git checkout kinect

http://www.openni.org/downloadfiles "OpenNI Compliant Middleware Binaries"
Latest Unstable
download, for example, PrimeSense NITE Unstable Build for for Ubuntu 10.10 x64 (64-bit) v1.3.0.18 to ~/kinect
extract this archive:

 tar -jxvf NITE-Bin-Linux64-v1.3.0.18.tar.bz2

edit your Nite-VERSION/Data/Sample-*.xml files by filling in PrimeSense license and preferred resolution as reported by several guides online
demos are located in Nite-VERSION/Samples/Bin