If you go to your list of members, there is an option to promote to administrator. Once they are an admin, you can transfer ownership of the group to them, but you can't have more than one owner. Admins have all of the same privilages as owners.
at 2:46 PM on Oct. 24, 2008
Currently a group can only have one owner. However you can have as many admins as needed to help with running the group. Admins can not promote or demote other admins or send group bulletins.