Google recently launched Buzz which some see as an attempt to feature in the global social network scene currently dominated by Facebook, Linkedin, Twitter and a host of others. That’s prompted the debate some have been having about the pace social networks are gathering in their relevance to our increasingly digital lives. A survey released this January by the Pew Internet and American Life Project found that more than one-third of all Americans now have profiles on social-networking sites like Facebook, Twitter, and LinkedIn, up from just 8 percent in 2005. And it’s not primarily children or teenagers either: The average LinkedIn user is 40 years old; most Twitter users are now 35 and older; and people from 35 to 54 now represent the biggest group of users on Facebook. You can bet that except for some slight cultural and regional skews, the numbers globally are not too far off from the American profile.

Given what may be an impending social networks battle, it’s worth taking a quick look at these social networks and the niche areas each seems to have carved for itself prior to the recent arrival of Buzz. With more than 400 million users, Facebook is the 600 pound Gorilla that is by far the world’s largest social network; Twitter by contrast has only 18 million or so. As of February this year, LinkedIn had more than 60 million registered users, spanning more than 200 countries and territories worldwide. Google’s Gmail’s (the Buzz platform) monthly users numbered around 146 million as of July last year when it was upgraded from beta status.

Facebook is a great way to reconnect with old friends, stay in touch with colleagues and can be useful for getting the word out for building a community around new ideas and business ventures. Twitter is a micro-blogging site that lets you send out 140-character messages called “tweets” to a network of people who have opted to “follow” you, as well as to follow the updates of anyone in your network. People use Twitter to send short bits of useful information, such as business tips or links to interesting articles, to help build their visibility and make new contacts. Linkedin allows registered users to maintain a list of contact details of people they know and trust in business. The people in the list are called Connections. Users can invite anyone (whether a site user or not) to become a connection. So far, reminiscent of Microsoft’s initial attempt at internet dominance, Google has failed to penetrate the social network space as its original stab Orkut only really took off in Brazil and India and its second attempt Wave was seen to be too abstract to get any traction. Buzz is the latest answer designed to undermine Twitter and Facebook by leveraging its Gmail user base.

If you aren’t using social-media sites to interact with remote friends, glean new ideas or tap into career and business opportunities you are missing a trick. The access you get to people via Facebook, LinkedIn, Twitter and now Buzz is just not available any other way. If you are serious about gaining advantage in the digital world, social networks are no longer optional. LinkedIn for example profiles more than 360,000 businesses and organizations which can be used to gather invaluable intelligence on job openings and opportunities. Twitter offers an opportunity to provide followers with messages that are truly useful (or at least entertaining), so that they’re of value to them. The generally accepted wisdom is that social-network sites can become a time trap, so you need to plan the time you invest in them each week. However when used properly, social networking is one of today’s most cost-effective ways of building professional reputations, finding job opportunities and staying up-to-date with the latest industry news.

Bottom-line, social networking is all about quickly finding people! Especially that wonderful group of people who just might help you succeed in whatever it is you are aiming for.