Social networking is a new trend:

• Overstock.com launched Overstock.com Auctions: combining auctioning with SN.
• Buy.com bougt Metails.com: combining etail with SN.
• Lycos introduced Lycos Circles, extending to personal interests.
• Evite (IAC) added recommendations in order to increase traffic and site visit time.
• Similar offerings are from Judy's Book (which recently got funding), Idealab's Insider Pages, Yelp! and local-i.
• eBay supposedly will launch a 'new community', possibly through Yelp!