Wow, is Earth a hectic planet or what? The user-generated documentary "Life in a Day" is a trove of YouTube footage shot by volunteers around the globe on July 24, 2010, and sifted into some semblance of shape by veteran director Kevin Macdonald. Macdonald is a formidable moviemaker. His account of a two-man mountain-climbing disaster, "Touching the Void," is genuinely unforgettable. But making sense of a mass of 4,500 hours of crowd-sourced home movies is a job for a magician. Almost inevitably, a film made from these snippets is less than the sum of its parts.

We see tranquil elephants swimming by moonlight, deadly human stampedes, the aurora borealis, a man brushing his hair, major cities bustling, straight-to-the-camera confessions, even a tracking shot of a woman skydiver. And needless to say, house cats.

Macdonald's efforts to forge these mundane and magnificent images into a chain of life produces lots of jangling but little cohesion. One Manhattanite gets his coffee from a street-corner barista; another brews his on a campfire on the snow-capped mountains of Nepal. Duuuude.

"Life in a Day" feels like a 95-minute Flickr photo stream. Pretty pictures, scant continuity, none too edifying.

The film presents itself as a human tapestry of rich and royal hue, but it's a monument to voyeurism and exhibitionism in the Internet age. In the final straight-to-camera segment, a young woman tearfully laments that nothing worth recording happened in her day. If this project hadn't dangled 15 seconds of fame before her, would the need for "something" to happen be so painful?