Google Base is a general purpose metadata registry and cataloging service that allows users to create records that describe digital and physical objects. Google may use this metadata to create stand-alone services like eBay and craigslist and/or to enhance Google's regular search results with guided navigation.
Or maybe not. It's actually quite difficult to define. Right now, it's chock full of porn, spam, and information architecture. In all this confusion, I'm hoping to get rich quick by selling this chair. The ability to tag physical objects is certainly interesting. If nothing else, Google Base brings us one step closer to UFOs.