Looking for a job -- particularly in these desperate times -- is an unenviable task. Besides the shame of whoring yourself out to potential employers -- hopefully just in the figurative sense -- you'll have to endure a slew of unsolicited suggestions from employed friends and acquaintances.

Consider yourself lucky if you've never heard helpful tips like: "Refuse to be a statistic."

But after exhausting all their "concerned friend" expressions, your buddies are almost guaranteed to ask one crucial question: "Well, are you on LinkedIn?"

If you answer yes, your friend will probably be fresh out of cliches -- with the possible exception of "Good luck."

LinkedIn is a social network specializing in the job trade. Rather than posting movie interests and quiz results showing which Hawaii Five-O character you'd be, users list details about their employment history, education, awards, and so on. LinkedIn members don't simply post an online resume: They "connect" with one another based on shared work history and mutual colleagues, thereby expanding their list of business contacts.

It's a Facebook for jobs. Minus the drunken party pics.

Launched in May 2003, the site's already made quite a splash. According to its fact page, there are over 42 million users representing 170 industries in 200 countries. Personal accounts are free, but there are several pay accounts available with features such as reference searches and unlimited user access.

The site benefited from a huge uptick in traffic due to the recession and massive layoffs. In January, the number of unique visitors rose 22% to 7.7 million compared to December's 6.3 million. More notably, total time spent on the site doubled to 96.8 million minutes -- or roughly 1,034 years -- spread across its dedicated user base.

The site's business model has proven extremely popular with investors -- all without flashy ads or an eye-catching layout. The site was profitable in 2008, raising over $100 million from backers including Sequoia Capital (SEQUX), Greylock Partners (which has also invested in Facebook), and Goldman Sachs (GS). It expects to be profitable this year, as well.