[lvecsey]

How about a 4chan style message board in the sense that posts expire very rapidly, but also in that only single topics are allowed for certain time intervals. For example the site could start off with a 24 hour cycle in that dialog can take place on a certain topic (such as BP oil spill) based on the first message that has come in that day. It'll need some means of aggressively pruning out (marking as spam) messages that are deemed off topic, but this can be a voluntary (karma based) or a machine learning approach that could also be tweaked or plugged in beyond the 4 week development period. The initial version would just keep topics on lock down for an additional 24 hour period, before permanent deletion. So basically there is one active topic, and one previous topic for review.