Well, sorry to be so low-tech and all, but I tackle this problem in a couple of ways:<p>1. A (private) blog - person with the idea posts it, discussion happens in the comments. Pluses: Easy, clients for everything under the sun, easy mail gateways etc. Minuses: Someone has to cull the important stuff into an actionable request.<p>2. Our fault tracking system (homebrew but think bugzilla) - someone posts something (severity=wishlist) - you can close it if the discussion goes nowhere, or turn it into an active item if there is a conclusion. Pluses: very searchable, keeps all know-how about the project in one place. Minuses: Not the friendliest UI on the planet.<p>Seeing the words "startup" and "3-person team", my gut reaction is "don't ovethink this".