The DavidonDemand page says: “David Perez wanted to go to the Advertising Festival in Cannes. Leo Burnett agreed to send him, on one condition — he has to do anything you tweet him. What will he do next? That’s up to you.”

And he’s not kidding. If you tune into DavidonDemand, there’s a live camera showing Perez going about his biz at Cannes flanked by a live Twitter feed with orders from viewers. Perez also has a pair of glasses armed with a built-in web cam for a first person POV on some of his adventures.

On Day 1 of this weeklong extravaganza, at the behest of his twittering fans, Perez spilled a drink on himself, walked on water, kissed a stranger, touched a Lion (the big deal ad award), ran after a jogger and got tattoos. Not in some discrete body area but on his right shoulder. Three of them. Including a huge twitter fail whale and the handles of two complete strangers.

This morning, Perez – a Chicago-based recruiter with Leo Burnett – has been lolling on a boat.

“We’re on a motherchucking boat – for all you children at home watching DavidonDemand, I said motherchucking.”

The twitterers seem to want him to shave or get a haircut. One request: “(Get a) mohawk!… and shave a penis into the side of it.”

“Draw a picture of a monkey eating sushi while on the boat,” asks another.

He’s singing people’s names, “The Marseilles” (well, trying to), and jabbering non-stop.

It’s a weird, Trumanesque experiment, especially because Perez is no spineless patsy. He talks back. He tells the twittering hordes what to tweet.

“Internet, tweet Yahoo and get me an invitation to the Ben Stiller thing tonight.”

Then: “Internet, tweet me something for my throat cuz I’m not gonna have a voice in three hours.”

It’s ridiculous most of the time, perversely riveting always. But that has little to do with the technology and more to do with Perez himself: the guy’s charming, a seriously charismatic sweet talker.

It’s about an hour since we tuned in. He’s still on the boat.

“Hey internet, can you do me a favor? Can you tweet Jessica Simpson and tell her we’ve found chicken of the sea?”

Some fool tweets in: “Can you type ‘hyperless’ on your forehead?”

“Oh my God – is that Dick Van Dyke?” Perez shouts excitedly as a yacht passes by.

All week, folks, all week.

UPDATE: Turns out that DavidonDemand is the most tweeted thing at Cannes, beating out even Facebook’s Mark Zuckerberg.