Update: The plugin has been released and can be downloaded from this page
Recently I was developing a website for a client who is a real estate agent. They wanted to integrate a property search into their site and after searching for an open service I came across Trulia, who offer free online services to estate agents and brokers.
Trulia offers integrated search and custom property feeds, but they also enable an agent to submit listings to the site via an XML feed. These listings can then be viewed on a Trulia map (Google Map) from within the agents website. Seems like a very nice feature for free.
Most of the sites I design are based around using Wordpress as a CMS. Although, I have never developed a Wordpress Plugin. So I have decided to create a Plugin that will enable real estate agents with Wordpress based websites, there must be a few of you at least ;), to generate Trulia formatted feeds (including property image uploading/resizing).
I have started development today and will keep progress updated here
Update #1: The plugin development is over half way there will hopefully be a release within the next week if I get enough time to work on it.
Update #2 (2006-10-01): Here

Hi Dave,
This sounds exciting! I do a lot of feed integration work at Trulia and would love to offer any help you may need on this project. Looking forward to seeing the Trulia plugin in action!
You can reach me at “n i s h e e t h at t r u l i a dot c o m”.
Thanks!
Nisheeth
Thanks Nisheeth, I”ve just emailed you.