Wired.com has a great piece up this morning comparing Craigslist and Tribe.net.
Of everything going on in the social software market, I think this may be the most interesting battle to watch. While Friendster vs. Match.com may be more interesting in the short run, Personals has never been as big a business as For Sale and Jobs.
One thing is for sure, the newspapers are going to be the losers in this battle unless they get busy and start buying up these services.