These aren't your teenager's social networking sites.

Take a spin on MySpace and Friendster and most adults find amusement in the concept and technology, but relatively few practical reasons to keep coming back for more. They've been a boon to a mostly younger set of users looking to meet new friends, find a date, or just generally kill some time online.

An increasing number of professionals are tapping into a new breed of networking Web sites to do more than just boast about how many "friends" they have. Millions of users each day are using the Internet to compare investment techniques, correspond with job recruiters and find help in launching a business.

Sites are also being designed specifically with professionals in mind. LinkedIn, a business-contact networking site, has seen its ranks swell to 12 million in just four years. And online brokers, including TradeKing and Zecco, are using social networking to let investors swap stock tips.

Get the full story at the Houston Chronicle