StayPress was announced yesterday (and pimped by none other than Matt Mullenweg), and it looks promising. In the words of the creator, Barry:
StayPress is a collection of plugins that will turn a standard vanilla installation of WordPress or WordPress MU into a property management and bookings system. Of course when I say Property, I actually mean any bookable resource of which there is a finite availability. So the StayPress system will be able to manage property rentals, hotel room rentals, conference rooms and centres, B and B’s, training rooms, bands, etc…
This will be one to follow. The plugin collection isn’t out yet, but will be, and a hosted version is on the way as well. Reminds me of BuddyPress, which is now an Automattic project, another implementation of a WordPress based project (although BuddyPress builds on WordPress MU).