It would be extremely helpful to be able to filter my budget report so I can easily see only categories that I have not budgeted for but were used.
What I currently have to do is run a report and include all categories, and then carefully go through the results trying to see if there are any non-zero actuals that are not budgeted. I think this could be an addition on the Advanced tab for budget reports on the categories filter. Add "Non-Zero actual/not budgeted.