Multiple Administrators

This might already be possible, but I haven't figured out how to do this yet if it is.

I am looking to set up a simple database, and share it with a few friends. I want those friends to have full privileges and be able to edit all the data. I also want the general public to be able to read/view the database, but not edit. Is this possible? If so, how? If not, please add it!

Basically:

Friends/Administrators/Moderators -> Full access
Public -> Read-only

Btw, this is a great web app, keep up the awesome work you guys.