Processing.org. CreativeApplications.Net. Gallery « Butterfly. Kinect and Processing. This is all very preliminary, but here is a first pass as a Processing Kinect library: (Mac OSX only for now, sorry!)
UPDATE (12/18/10): New version of the library can be downloaded from github: openkinect.zip. Source: None of this would have been possible without the heroic efforts of Hector Martin, the OpenKinect project, and various members of the openFrameworks community. Processing Workshop.