Here are a couple of files which I hacked together to enable communications with openni's SingleControl with a node.js socket server which would then be used by a ui layer such as flash.
 
To try it, replace main.cpp in SingleControl and run the make-single.sh script or re-run the entire make.

notes:
1. I'm assuming a lot of things here i.e. openni, nite & sensor are already installed and ready to go on your machine.
2. This is meant for the mac. I haven't tested this on linux or win. Let me know if they work.
3.  All this inspired by BlitzLabs (http://labs.blitzagency.com/?p=2634).

Happy hacking.

02/06/11 - kevin