Is there a good place on this forum somewhere (I guess the shortform but it doesn't get many views)?
A Facebook group (a friend suggested creating a Facebook group called "Butterfly Ideas" so if anyone has the energy to do this right now, I would join that group!)?
Somewhere else where you can throw out an idea that you know is under-developed and get the pushback needed to develop it further? (a friend said Twitter can be quite good for this because there is less of an expectation for ideas to be polished)
Seconding this. Spencer Greenberg's approach is to tweet, collect feedback, write a facebook post that incorporates the feedback, collect feedback and then turn it into a blog post.