As part of the release of the new 3.0 beta of Google Desktop, Google has released a beta of a new eBay plugin they developed called eBay Watcher. The plugin, or "panel" as they call it, allows you to keep track of items on your eBay watch list. I got involved in the project by providing feedback on early versions of the product and by helping to ensure that they got certified in time for launch.
The plugin is a great example of what can be done using eBay Web Services. All of the data is retrieved using the Unified XML API, using calls like GeteBayBuying. They also take advantage of the new capability that we offer to rate limit API calls by User ID.
I met the product manager for the project at the PDC back in September, where I pitched the idea of an eBay plugin for the Google Sidebar. A few months later when they approached us about the plugin I asked him if they had started this project because of my suggestion. He said that they had already had something like this in mind at the time, but it is still nice to see my evangelism efforts having some tangible effect.
Congrats to Google for putting together a great product. Hope we get a chance to work together on more great stuff in the future.