When you have a complicated workbook with a lot of variables (fields) and calculations it would be nice to have a designated spot in that window where new calculations appear automatically.
It stops you having to scroll and look for your new calculations. You could let the user invoke this feature. ie. if a user creates a folder called "NEW CALCS" then any new calculations (maybe limit it to the last 4 or 5) appear in this folder by default. It is infrequent that you make 1 new calc when doing something, so its nice to give these calcs a natural grouping, initially.