I just finished reviewing some of my answers today, to questions that are fairly old but have valid answers from multiple posters.
I thought it might be interesting to have a feature of Server Fault to notify OPs about open questions they might have, similar to how you can receive notifications about responses to questions, etc.
Maybe the best use case would be for users under a certain reputation level to receive e-mails once a week or once a month as a reminder. Then after meeting a certain level you have the option to disable the message.
It might help to narrow down our open question list a bit and encourage new users to help in marking questions as answered and not forgeting about them once they get the answer they need.
What does the community think?