Here is a nifty little feature that we just added. You can now run a Query, go to an Organization, and add everyone in the Last Query directly into your Organization. This is not the usual way to add Members to an Organization.  However, for example, if you are creating an Organization and need to enroll everyone who is also enrolled in any of several other Organizations, you could run a Query to find those people and then add them very easily to the new Organization using this feature.

Update: this only works for Admin right now. We'll open it up soon.

You will find this option when you select Add from Tag on the Organization page. There is an option near the top named (last query) . When you select it and click OK, everyone from the last Query that you ran will be added as Members to that Organization.

Read more about Adding and Removing Organization Members using Tags.