Adafruit Industries - a NYC based company that sells kits and parts for original, open source hardware electronics projects - is offering a 2000 USD cash prize for whoever is first to release an open-source PC driver for the Kinect:

Hi from team Adafruit, we’re going to do our first ever “X prize” type project. Hack the Kinect for Xbox 360 and claim the $2,000 bounty!

What do we (all) want?
Open source drivers for this cool USB device, the drivers and/or application can run on any operating system – but completely documented and under an open source license. To demonstrate the driver you must also write an application with one “window” showing video (640 x 480) and one window showing depth. Upload all of this to GitHub.

How get the bounty ($2,000 USD)
Anyone around the world can work on this, including Microsoft Upload your code, examples and documentation to GitHub. First person / group to get RGB out with distance values being used wins, you’re smart – you know what would be useful for the community out there. All the code needs to be open source and/or public domain. Email us a link to the repository, we and some “other” Kinect for Xbox 360 hackers will check it out – if it’s good to go, you’ll get the $2,000 bounty!
CNet already has a response from Microsoft and they love the idea... Oh, wait, no... Actually:

“Microsoft does not condone the modification of its products,” a company spokesperson told CNET. “With Kinect, Microsoft built in numerous hardware and software safeguards designed to reduce the chances of product tampering. Microsoft will continue to make advances in these types of safeguards and work closely with law enforcement and product safety groups to keep Kinect tamper-resistant.”
Official Site: adafruit.com