HN Idea: a subforum for creating and critiquing startup ideas

If there's one thing the HN community does really well, it's to constructively critique ideas. Unfortunately that often happens after a lot of time and effort has already been invested in a project.

I think it'd be awesome to have something along the lines of the "Ask HN", but specifically for startup ideas.

Some of these ideas will come out fully baked, but what I would hope for is somewhat of a playful tone and an acceptance of half baked ideas. Some of them might even hopefully be incredibly ridiculous (What about something like this? http://www.youtube.com/watch?v=EFZo5xXukec ).