Amidst boatloads of people exploring the promise of online video, Justin Kan is, without a doubt, the most extreme.

Yesterday I joined Kan, who’s live-streaming his life 24/7 using a camera strapped to the side of his head, at the local climbing gym. Unfortunately just before I got there he had dislodged a wire while dismounting the bouldering wall, and his video feed was out.

You could see each second of the technical difficulties ticking away at him, so we agreed to reschedule the interview. He declined to give me his personal phone or IM handle on the air (as the audio feed was still working) for fear that it would be spammed too.

Twenty-three-year-old Kan, who lists one of his cell numbers on his website, has been called, texted non-stop since the experiment went public Monday. He shows me a text message from an overeager fan who has traced the phone numbers and addresses of all Kan’s coworkers (that is, “castmates”).

Kan claims it’s all in good fun, that the positive outweighs the negative. Later that night, the gang calls me excitedly from the Y Combinator office in Mountain View, where some fans have just ordered a surprise pizza delivery. (Y Combinator funds the project as it did the team’s prior effort, the Kiko web calendar.)

Back at the gym, I resign myself to getting some climbing done on my own, until Kan appears, looking much happier. “Three people called me to say the video is back up!” he says. We sit down for an interview (you can see a clip of it here). Kan tells me he’s trying to prove the concept of 24/7 reality TV by doing it himself — the team wants to create a platform for other exhibitionists. Maybe even a real-life Sex in the City-type chick will sign on, Kan hopes.

We chat about the too-much-information aspect of what he’s doing. Kan says he wants the show to be PG-13 or R at most, and so he turns the camera to the ceiling when he goes to the bathroom. “So you’re probably not going to get a lot of action during the experiment,” I comment. “Well, there are differing opinions on that,” he replies. I’m later told by a friend who’s watching the live feed that the chat room goes crazy at this point.

The ability to interact with viewers is key part of the real-life Truman Show Kan has created for himself. The easiest way for them to get involved is to hop onto the live chat on Justin.tv. Fans dissect his surroundings, ask him for shout-outs, and act generally like you’d expect people who’ve become fans of a guy with a camera on his head to act. Many people who call him are so surprised when he answers that they hang up.

Kan is pretty mellow for such an exhibitionist — he’s not some crazy Big Brother or Real World contender. He says he grew accustomed to the rig by wearing it for 76 days prior to the launch. “So what about other people?” I ask as he pans his camera around the climbing gym simply by moving his head. “These people haven’t signed waivers.”

“Thanks for bringing that up,” Kan replies. He says some people are uncomfortable with the camera, and that’s fine. “But I’m not taking it off,” he says. “If someone wants to talk to me, this is the context they’re talking to me in.”

He holds up his phone when we’re done chatting. Twenty-three missed calls.

This morning when I check in on Justin, who’d pointed his camera at himself before going to bed, the first chat room message was from user “danielha,” saying “i have to sleep when justin sleeps. new rule.”