With this Bulk Directory editing and updating tool from BetterCloud, you can quickly export your entire directory (or any customized view of it) to a Google Spreadsheet, make updates, and then import those changes to your Google Apps Domain.

This is very useful when you have a class of students moving from one Org. Unit to another, or any other time you need to make the same change to a large number of user accounts. Check out this video to learn more.