A standing-room-only crowd of some of the most experienced venture capitalists discovered they still hadn't seen it all on Monday when South Korean startup MusicShake kicked off its presentation at the TechCrunch40 Conference by playing a catchy dance tune, only to disclose that it had been composed by a 9-year-old using a PC.

MusicShake, an online amateur music-mixing service that also calls itself the composing site that even your grandparents can use, offers users a collection of menus from which to chose a music genre, beat, vocals and sound effects, along with a sophisticated program for mixing them into professional-sounding tunes. As the company founders played a broad sampling of music composed on its site by nonmusicians, most of the people in the conference audience stopped their multitasking, looked up from their laptops and listened in awe, finally breaking into a resounding applause.

At a time when the term Web 2.0 is typically applied to the usual mix of blogs, online photo albums and amateur videos, this startup and some of the others at the conference demonstrated that entrepreneurs have barely scratched the surface of the services they can whip up with the help of a computer and a mouse.

The variety of business plans also demonstrated that not all user-generated content is created equal. While a site like MusicShake dumbed down the process of making music, 8020 Publishing, which puts out slick magazines such as the travel book Everywhere, mines undiscovered talent. 8020's magazines are created with editorial and photographic submissions from a generally nonprofessional community of Internet users who have interest or experience in a given topic. Ponoko, meanwhile, is a Web site that lets users create products, such as jewelry, toys and furniture, and offers packaging and marketing support to get these creations to consumers.

Because these sites offer ways for amateurs to put their creations up for sale, they also signal a potential explosion in the range of Web 2.0 services. While many of these companies will eventually have to address copyright and other legal matters, those unresolved issues won't slow consumers from using these services any more than they slowed people from watching YouTube. - Andrea Orr