https://bitcoinstarter.com/Is one that has been around along time.
The only problem with it is that people generally have very bad ideas. Other than that it's a good site.
Well, maybe we could change that. I've wanted to turn a sci-fi story I've self-published into an indie movie for a long time but just haven't had the startup funds to do it, and of course I'm not going to have a lot of luck with fundraising without a good trailer. Anybody else have an idea?