Google Base is now available to the public. This service from Google allows you to post or find information on a variety of subjects, from parties, to events, to selling cars, and lots more.
The biggest problem with this site is that you can't classify it, like you can other sites (such as Amazon, eBay, TV Guide, etc.). It seems to incorporate a lot of features of a lot different sites into one big mishmash of a site.
Before this site was available people were speculating it was going to compete directly with eBay. Although, the more you dig into it the more you find that its not specifically true. Maybe one day it will, right now its not.
IMHO is more like a big electronic bulletin board that people can post or sell anything that they want. If you want to post, it does require that you to have a Google account.