I’ve modified the excellent RS Event WordPress plugin to include two new fields: an original URL and a location; as well as an output filter that writes the event information into the post itself. The goal is to eventually use that to provide an hCalendar microformat for event listings.
I haven’t contributed these changes back Rob Sargent yet, but I plan to. In the meantime, feel free to grab a copy the GPL’d code and take a look yourself.
Download RS Event Mod 0.9.3.1.