Wow, this kind of struck me in a meta context because I just had an idea the other day for a site cataloging ideas for startups or various other things. Call it IdeaBin or something like that. People could claim interest or indicate that they've worked on an idea. Existing versions of those ideas can be linked to. Duplicates could be a place to bring authors with similar ideas together to collaborate.
But, of course, it's still just an idea :)