10 things you didn't know about Facebook (including why your friends are addicted to it)

6. Surprise, you don't have to grow up
Punching in at work is many a dreamer's concession to grown-up life ('til that million-dollar lottery win, right?), but Facebooking on the company dime is one relatively benign form of rebellion. It's actually a pretty good 4 p.m. time-waster (and yes, you do need those -- hey, they cut work burnout and stress!). But isn't self-obsessively updating, editing, constantly polishing one's profile, searching old friends and uploading vacation photos sort of...immature? In all honesty? A bit. But so what? Log on, and you'll find other thirty- and fortysomethings as irreverent as you. Perhaps in the group Parents Who Joined Facebook To Spy On Their Kids And Then Became Addicted.

7. Don't worry, you can say no to friend requests
As with any social networking on the Internet, don't be surprised if guys you know contact you on Facebook. No interest in communicating? Ignore their e-mails and deny their Friend Request (don't worry, they won't know: it'll just look like you never got around to replying, not that you Declined). And if you're single and they seem interesting? Feel free to meet in a Starbucks or other busy public place (tell friends where you are going, or even have them sit at a nearby table), but don't be too disappointed if he either refuses to meet you (or always has excuses), or if Mr. Fab Online is Mr. Flat In Person. For many, "doing real life" is a less attractive option than Facebook's controlled environment, where every post can be witty, every photo can be flatteringly well lit.

"The person who always chooses to communicate through the web may [have] some psychological issues," says Laura Corona, a San Diego-based web psychologist. "People who have issues with real-life commitments will prefer IM or e-mail over real phone conversations," says Corona, who has online-counseled adults dealing with web addiction.

8. It won't suck up all your time. You'll get bored with it eventually.
By all accounts, Facebook addiction is at its height right after you join. "I was checking my Facebook every 15 minutes when I first signed up, but now not as often," says Natasha Kong, a Salt Spring Island, B.C., art director. The fever pitch of addiction seems to be at its hottest when you're neck deep in searching old flames and childhood friends. Then? Often you find there's nowhere to go from there, and use it to chat with your real friends.

9. It's quirky. You can make it even more so
Those little gift icons you can give to your friends for $1? They were designed by Susan Kare, who did the original set of icons for Macintosh in 1988, which adds to its hipster cred. Since Facebook's spring 2007 open invitation for programmers to design additional applications for the site, free applications such as Fortune Cookie (ask a question, get an answer), Honesty Box (send anonymous messages and be totally honest without fear of social sanction) and Places I've Been (a world map with pins showing where you've jet-setted to) are further adding to its design-power-to-the-people populist appeal -- and smartly extending its shelf life where more static predecessors like Friendster failed.

10. Use Facebook wisely: you still should schedule face time
While critics argue social networking websites are a less authentic way of interaction than meeting in person, Facebook spokesperson Matt Hicks says the school-, work- or geographic-network-based nature of the site is "strengthening real-world relationships, not replacing them. Facebook also has applications that allow people to organize events held offline, for example," he adds. In other words, the best way to use Facebook? Don't mistake the social networking tool for an actual social network. Schmooze it, or you're misusing it. Use it to schedule face time with your friends, set up work meetings, and spark dining table conversation with your kids.

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