When I go to the unanswered section I see "smart" Questions with high votes what I want to say is that those question actually don't lack an answer they are just appealing. With a random button one could help more People don't you agree?
Edit:
If you go to the mainsite, and then choose Questions on the left field and then go to Unanswered you see question that have already been answered in Mathoverflow but are still marked as Unanswered. I don't like it. I would prefer to have a possibilty to get an answer for an unanswered question older than 2 days. There is already an unanswered section on the sidebar - I am Aware of it but those too are listed from newest to oldest. With something like a random button which would yield unanswered Questions Independent of their release date - I could hope to get an anwer for old unans. questions