More people are turning to the Web to watch television shows and movies, thanks to sites like YouTube and Apple’s iTunes store. But there’s an emerging breed of website that’s letting people go beyond passively viewing video. A number of startups, including Jumpcut, Grouper, and Motionbox, are providing free software tools that let anyone mix video clips online and, in some cases, make movies even if they don’t have content of their own.

Yahoo, based in Sunnyvale, CA, recently acquired Jumpcut after looking at the trajectory of Internet video, says Jason Zajac, general manager of social media at Yahoo. He says that more people are participating in online content creation than ever before, from publishing photos on Flickr to sharing bookmarked webpages on Delicious (both companies are owned by Yahoo). For Yahoo, Zajac says, Jumpcut had the best approach and technology to effectively stir the average person to put together personal movies.

Jumpcut has “enabled real-time video editing through the Web browser,” says Mike Folgner, cofounder of the company. Using an advanced Flash-based application, people can preview changes while editing. “This real-time feedback mimics the desktop editing experience that people are used to,” Folgner says.

Using the software is straightforward. You can upload your own video clips (each up to 100 megabytes in size) and then play around by changing their order, speeding up time, and adding special Flash effects that, for instance, make butterflies flutter across the screen. If the thought of starting a project with a blank slate seems daunting, there are plenty of clips and videos already available on Jumpcut, just waiting to be remixed. The preexisting clips are provided by other users and sponsors.

The corporate collaborations are part of Jumpcut’s business model: in an effort to increase brand awareness, companies provide clips and offer prizes for the best user-edited short videos. Previous contests include remixing the trailer to the 2006 film A Scanner Darkly and putting together a short movie from a collection of New Line horror-film clips. A current promotion sponsored by the chip company Doritos has put out a call for a user-edited chip commercial that will air during the Super Bowl. So far, more than 300 commercials have been submitted, and some of them are surprisingly good, says Yahoo’s Zajac.

The technology that’s driving Jumpcut’s site is based on the same Flash animation software that’s responsible for a growing number of interactive websites. When you upload a file on Jumpcut, your original file is saved on the Jumpcut servers, and a copy is converted to a Flash format. You edit the Flash version in the browser, and as you do, explains Zajac, you’re actually creating a set of Flash programming commands that are layered on top of the file. “You’re not actually changing the [original] video file,” he says. When you want to play the video, Jumpcut’s software reads the commands and presents a video that appears to be edited. This approach enables relatively fast editing. It also has advantages when it comes to copyright control. If a clip on Jumpcut has been found to be used illegally, Zajac says, the original file will be deleted from the server, automatically removing it from all Jumpcut videos that used the clip.

When you complete a movie on Jumpcut, you can assign a number of options for how other people can view or remix your work. You can keep it private, assign rights to friends only, or allow anyone to view and remix it. When you make your work “remixable,” says Zajac, anyone can grab bits of your movie and create their own movie around it. Taking this concept a step further, he says, you can choose to make your movie “open,” meaning that others can change your finished product, producing a sort of wikivideo. Choosing to make your movie open could be useful for school projects, in which many people collaborate, and for weddings and parties, so a number of guests who have created videos and snapped pictures can put them together.

Video production is moving from being something that only a specialist can do to being something that’s available to the masses, says Howard Rheingold, author of Smart Mobs: The Next Social Revolution and lecturer at Stanford University and University of California, Berkeley. “It’s getting easier and easier,” he says, “and the tools for production and distribution are becoming more widely available.” Jumpcut, he says, is an example of the convergence of online social networking and do-it-yourself media. “We’re seeing the beginning of something,” he adds.

While the Flash technology makes the site’s performance comparable to desktop video-editing software, Jumpcut’s capabilities are still somewhat limited. For instance, if you want to do more-advanced video processing, such as adjusting the lighting, you’re going to need to use desktop software. But for now, Jumpcut is offering a combination of simple tools that appeal to a growing number of people. Folgner says that his team of programmers will continue to add features to make editing, sharing, organizing, and collaborating easier for Jumpcut users.

And as the video recording hardware improves, Folgner expects to see even more user-generated content. “Personal media shared online will explode in the next five years,” he says, “which creates enormous opportunity for technologies that facilitate collaboration and creation.”