Hi, I've just released my first plugin. It is the first of a group of plugins in development to add property management functionality to WordPress.
This first plugin provides Booking management capabilities and a customisable Availability calendar and is aimed at rental property owners who use WordPress to promote their property, and currently use an external availability calendar.
Though I'm sure it could be put to other uses....
The URL of the release is here: http://blog.clearskys.net/2006/11/20/booking-manager-and-availability-calendar-plugin-v01a/
Installation and operating instructions are here: