This is a great tip that I saw at Convergence 2011. I was able to use it onsite with a customer the first week I returned. They were having issues with leaving all of Financial open when all they really wanted to do was leave open the Bank Deposit window. You can do this by opening and closing specific Windows (Origin) in the Mass Close window under the Fiscal Period window.

Administration>>Setup>>Company>>Fiscal Periods>>Mass Close

Change to the period that you are working with (last month)
Open the specific window (example: only open Bank Deposit Entry)
Click OK

Be sure to go back and re-close the Origin(s) that you opened.