I finally had some free time yesterday to explore the Windows Live Expo API and quickly whipped up a Live.com gadget which browses apartment and condo listings in a zip code of your choice. Given that we might be moving again this summer since a noisy bar opened across the street, this gadget will turn out to be quite handy. Below is a screenshot of the gadget.
You can add it to your Live.com page by going here and clicking . I didn't really have much problems with the Expo API beyond the fact that it only accepts latitudes and longitudes so I have to use the Yahoo! Geocoding API to convert zip codes to lat/long coordinates before calling the Expo API. The fact that they both used RESTful APIs definitely made writing this mashup a breeze.
I'd love to add a feature to the gadget where I can add an apartment I like to one of my collections in Windows Live Local since I already have a collection of "apartments we should check out" there already. However there are a number of issues which prevent this today. Of course, I know all the right folks to nag to make the changes that would make this possible. :)