Erica Sadun, a TUAW writer, analysed how AirPlay work at the protocol level.

She then applied this knowledge to write a small but amazing little application that will advertise your Mac as a target for AirPlay. You can see the result in action in the short youtube video below:

I tip my hat to Erica for coming up with such an application.  Now that the cat is out the bag I am sure there will be more like this to come. I hope Apple does not go out of it’s way and change the protocol to render Erica’s application non-functional.

You can download a copy of the AirPlayer application on Erica’s web site.

Hacksugar: Mac-based AirPlay service allows device-to-Mac playback.