"The Google AJAX Search API is an experimental API that lets you integrate a dynamic Google search module into your web pages so your users can mash up Google search results with other content on your site or add search results clippings to their own content."
The phone list from the video is actually a spreadsheet where you can copy results from Google Local. Imagine how this would look in Google Spreadsheets.
There are three gadgets for Google Personalized Homepage that use this API: video search that lets you create playlists based on search results, map search and the combined search (web, blogs, maps, videos).
I think Google UDS will have an interesting future and will be the foundation for many innovative mashups, like Google Maps API is today.