Move over, eBay and Craigslist. Google's getting into the classifieds business. Currently, the plan appears to target fixed-price offerings and not the auction business that eBay is best known for. Nevertheless, Google's entry into the fixed-price business could pose a threat for other classifieds sites, especially those with advertising at the core of their business model. eBay's fixed-price offering, called Buy It Now, currently makes up nearly 30 percent of its total gross merchandise volume. Google's new service, called Google Base, will rely on keyword-based advertising for revenue. Google Base is currently under development, and there's no word as yet on when the service will be publicly available.