From the Google Base blog

<quote>
You can insert, edit, or delete items programmatically, complementing existing input means like the Google Base front-end or the bulk upload mechanism. You can also query other users' published content and access their items via the API. This enables you to create domain-specific search applications (or mash-ups) combining Google Base content with other services.
</quote>

I can see where this could be have real potential expecially when mashed up with Google maps.

Links:
http://google-code-updates.blogspot.com/2006/08/new-gdata-api-google-base.html
http://code.google.com/apis/base/