Genius can prove more than one man can handle. That was the case with Syd Barrett, who apparently died a few days ago.

He co-founded Pink Floyd, but let drugs - particularly early and powerful versions of LSD - get the best of him and was forced from the band in 1968 in favor of David Gilmour. He had a brief solo career, but dropped from the public and the music industry around 1972.

His reclusion and eccentric state pushed him from fame to infamy. Though he checked out more than 30 years ago to the safety of his mother’s Cambridge basement, his creativity helped fuel the creation of psych rock. His presence (or lack of it) had been somehow comforting all these years, and he’ll be missed. Shine on, crazy diamond.

Monday morning’s Diane Rehm show targetted social networking sites like MySpace and Friendster. It taught me a new word: realspace. It’s a retronym that defines reality vs. virtual reality.

In realspace, I see friends face-to-face. They see the nuances of my expressions, and vice versa. You can glean a lot of that information - for instance, the quality of the friendship - more easily in realspace. This, I think, is an especially important concept for kids to learn in the Internet era: Know how to divide the wheat from the chaff when it comes to social media. What is a viral advertisement, and what is a non-commerical Web site? Who is an honest, well-intention friend on my list, and who is a potential sexual predator?

In MySpace, and on other social sites, that nuance of face-to-face contact is lost, replaced by consistency of action. That is, if I act in x manner on the Web, you have no means to expect otherwise unless I one day act in y manner out of the blue. You are who you want to portray yourself (at least more so) on the Web than you are in realspace, because in realspace I can more easily tell if you’re being disingenuous.

Which brings me to the concept of the avatar. In my dictionary: a variant phase or version of a continuing basic entity. It’s an extension of one’s self, a projection. Increasingly, people have a wholly valid version of themselves online. There’s nothing wrong with that.

But, the avatar concept invites abuse when that projection is out of phase with the projector. (That idea applies to the entire Web, not just social sites.) People can approach the Web like a party full of strangers. Think of the movie The Wedding Crashers. (OK, that may be a bad example, since the characters in it don’t misrepresent on the Web, but you get the idea.) Think of a plausible story, do your homework, and pass yourself off as whomever you please.

Managing your avatar will become more important as the Web ages. Who are you? How do people see you? How do you want people to see you? Are the answers to those questions the same on MySpace as they are in realspace?

If they’re not, you have even more questions to ask yourself.

And, lest I forget where I started, Rehm’s show had a message for parents. Join the social sites your kids do. Be the first one on their friends list. Monitor who they associated with. Be the chapperone at the party.

Actively supporting your kids in their Web endeavors can guide them to good consumption habits, teach them to know online treasure from trash, and make them productive and centered Web citizens.