Read about "extra security."
I have a numbers spreadsheet that contains personal information (bank #'s, passwords, etc). It is password protected. A couple of times I have had the spreadsheet opened and forgot to close it when I was called away from my desk. Luckily no one accessed my info. Is there a way to configure the spreadsheet to close automatically after a specified time period?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic