This isn't a new idea but it's hard to pull off. Especially if you look at the details, these are supposed to be mostly artistic projects(Yes coding is artistic) but not business ones.

I know Seth Godin is a fan of this type of concept.

http://sethgodin.typepad.com/seths_blog/2005/05/fundable_a_n...

Also here is a blog post by Kevin Kelly of wired Magazine http://www.kk.org/thetechnium/archives/2008/03/1000_true_fan...