Because it can undercut the newspapers, Craigslist has been characterized as the Wal-Mart of classified ads… Well, now Wal-Mart (NYSE: WMT) is looking to be the Wal-Mart of classifieds. Walmart.com is beta testing a classifieds service, powered by Oodle that allows the site’s shoppers to post free classifieds on all kinds of stuff: cars, RVs, apartments, etc. A spokesperson told Reuters that the idea is to offer its shoppers more items through its website that aren’t available in stores. Could it take off? The company doesn’t have much to lose by trying something like this, and in towns across America where Craigslist doesn’t command so much mindshare (not NYC and SF, for example), it will at least contribute something to the downward pressure on the newspapers’ ailing classifieds business.