Two years ago, a YouTube member named MadV—who silently performs magic tricks while wearing a Guy Fawkes mask—put up a short, cryptic video. He held his hand up to the camera, showing what he'd written on his palm: "One World." Then he urged viewers to respond.

The video was just 41 seconds long, but it caught people's imagination. Within a few days, hundreds of YouTube users had posted videos—shot on webcams, usually in their bedrooms—displaying their own scrawled messages: "Don't quit!" "Tread gently." "Think." "Carpe diem." "Open your eyes." And my favorite, "They could be gone tomorrow!"

Soon, MadV had inspired 2,000 replies, making it the most-responded-to video in YouTube's history. MadV stitched them all together into a long, voiceless montage, and it's quite powerful. All these people from across the globe convey something incredibly evocative while remaining completely mute.

So here's my question: What exactly is this? What do you call MadV's project? It isn't quite a documentary; it isn't exactly a conversation or a commentary, either. It's some curious mongrel form. And it would have been inconceivable before the Internet and cheap webcams—prohibitively expensive and difficult to pull off.

This is what's so fascinating about online video culture. DIY tools for shooting, editing, and broadcasting video aren't just changing who uses the medium. They're changing how we use it. We're developing a new language of video—forms that let us say different things and maybe even think in different ways.

Here's another example: a new trend on Flickr called the long portraitt. These are short videos in which the subjects simply stare into the camera. The first time you see one, it's unsettlingly intense. The subject's gaze—staring at you—totally discombobulates the normal voyeuristic payload of a photo. It's also a lovely comment on the hyperkinetic style of today's world: Slow down and look at something, will you!

What's happening to video is like what happened to word processing. Back in the '70s and early '80s, publishing was a rarefied, expert job. Then Apple's WYSIWYG interface made it drop-dead easy, enabling an explosion of weird new forms of micropublishing and zines. Laptop audio editing did the same thing, giving birth to the mashup and cut-and-paste subgenres of music. Then there's photo manipulation, once a rarefied propaganda technique. Photoshop made it a folk art.

In a sense, you could argue that even after 100 years of moving pictures, we still don't know what video is for. The sheer cost of creating it meant we used it for a stiflingly narrow set of purposes: news, documentaries, instructional presentations.

Now the lid is blowing off. The Internet has shown us that video is also good for mass-distributed conversation—as with Talmudic response chains on YouTube or Vimeo, or even the super-short Twitter-like blurts of video on Seesmic. I know people who use Skype for virtual closeness, leaving a video channel to their spouses open all day long while they work. They're not even looking at the feed or talking; it's like emotional wallpaper. Who would have thought of doing that with a $10,000 videoconferencing rig?

Marshall McLuhan pointed out that whenever we get our hands on a new medium we tend to use it like older ones. Early TV broadcasts consisted of guys sitting around reading radio scripts because nobody had realized yet that TV could tell stories differently. It's the same with much of today's webcam video; most people still try to emulate TV and film. Only weirdos like MadV are really exploring its potential.

A bigger leap will occur when we get better tools for archiving and searching video. Then we'll start using it the way we use paper or word processing: to take notes or mull over a problem, like Tom Cruise flipping through scenes at the beginning of Minority Report. We think of video as a way to communicate with others—but it's becoming a way to communicate with ourselves. (Author Appreciation: Clive Thompson on How YouTube Changes the Way we Think, posted on 12.22.2008)