> the asker just never bothered to click accept . . . and the original user is evidently no longer interested in getting it answered.
I find this very annoying, too. I can understand why it would happen from the point of view of the asker: he might have found the answer on some other website 5 minutes later, or he might have just decided to find a workaround. Still, I think SO should remind people to accept answers (penalize them for having low accept rates) or have the most upvoted answer selected automatically after a while. Nobody wants to write detailed answers for someone who isn't interested in the question anymore.
In theory, the system's "economics" encourage askers to accept an answer, as askers with low acceptance rates will receive fewer quality responses (and often comments reiterating the phenomenon). But there's little incentive for drive-by askers with no engagement with the community, such as it is, to choose an answer; a consequence of SO's growing popularity is that these users comprise the largest group (901K users with between 1 and 200 reputation).
There should probably be some mechanism by which moderators or other trusted users can, after a time, accept an answer for such abandoned questions. Perhaps questions thus answered would be treated slightly differently (and identified differently in the UI); the original asker could always return and override the proxy acceptance.
> * Still, I think SO should remind people to accept answers*
It does. Your accept rate is displayed under your username when you ask a question. Let it drop to low and other users will start complaining in the comments under your question, telling you to start accepting if you expect answers.
I find this very annoying, too. I can understand why it would happen from the point of view of the asker: he might have found the answer on some other website 5 minutes later, or he might have just decided to find a workaround. Still, I think SO should remind people to accept answers (penalize them for having low accept rates) or have the most upvoted answer selected automatically after a while. Nobody wants to write detailed answers for someone who isn't interested in the question anymore.