I wondered if there was any merit in a system that encourages original posters to 'close' their questions by either selecting a 'correct' answer (as already done now) OR marking the original question as 'not solved' etc. This might lead to more questions being 'tied up' rather than apparently abandoned by the original poster with no feedback from them. Perhaps a 'n' point deduction from the original poster's reputation for every week(?) they do not 'close' a question?
Any thoughts?