ReVou promises “Twitter clone software made affordable” for $399 as a self hosted script. The script offers all of Twitters features, including SMS support, and even comes with its own API. The only question then becomes is why would you want to host your own Twitter? This is what ReVou says:
Existing site owners can benefit from running a micro blogging service resulting in more viral growth for your website when your users interact with follow friends by receiving updates via our social network platform. With our SMS integration as well as custom API, we allow you to gain more revenues through purchase of SMS credits, revenues from web advertisements and as well benefiting from 3rd party applications built for your site using our API.
Naturally I’m a little skeptical but there is a thriving marketplace for Digg style voting sites, with some services (Sphinn comes to mind) doing particularly well in various verticals. Perhaps there’s no reason why Twitter clones might not have some success, be it as stand alone sites or more likely integrated into existing membership based sites.