YouTube sensations are a dime a dozen these days—hello, Justin Bieber. But combine director Ridley Scott and a plea to the masses to crowd-source his latest production, and you end up with 4,500 hours of submitted footage to wade through. And of course, more isn’t always better, as the editor of Life in a Day, Joe Walker, is well aware, having grappled with the communal film project for the past year.

The documentary, which premiered at Sundance this week, showcases 1000 clips, drawing mostly from 26 directors who submitted footage shot on a single day, July 24, 2010. The sometimes tearjerking footage includes skydiving, shoplifting and spectacular stunts. One crew favorite included a naked man climbing a tree and pouring milk on himself. Sadly, says Walker, it didn’t make it in.

“I basically hired 23 kids out of London film school, got them all in a room, and trained them and developed a sort of strange star system to rate the footage,” Walker explained about the information overload. “We would have daily screenings where we would watch what was the pick of the crop, and we had a system where if we were looking for, say, a Bolivian nun, then we were able to look it up.”

YouTube, a film sponsor, flew the directors who made the cut to Sundance for the premiere. “We basically fill an entire hotel,” laughs Walker. He’s literally pieced these people’s lives together.

Life in a Day will be released in theaters July 24, 2011, exactly one year later.