The arrival of the website, at www.mtvflux.co.uk, will be followed on 6 September by a Flux TV channel. The channel will feature music videos, determined by Flux members, with additional user-generated content and text-to-screen applications.
The website will allow users to create their own personalised on-screen identity. "Fluxers" will also be able to communicate via mobiles by texting each other using their identities, or avatars.
Viacom Brand Solutions will sell advertising on Flux for MTV parent company Viacom. VBS managing director Nick Bampton said: "For the first time in the UK, MTV Flux will enable advertisers to reach a music, media and tech-savvy community across a number of platforms in an ongoing relationship.
"User-generated content and social networking are increasingly popular trends. Not only does MTV Flux tap into the heart of these, it offers something never seen before."
Flux will exist in the UK before it is launched in any other market, the US included. Viacom claims it will provide advertisers with a route to the hard to reach 16-24 market, and that its strategy has an advantage over alternatives like ITV's community website, Friends Reunited, because it is based around its existing core audience.