We have one master Big Ten Club account for MailChimp. It's free up to 2,000 members and as of 06/07/12 we have 1,553 on the list. Login and password info is located in the 2nd tab in the google Contacts sheet.
The master MailChimp list is segmented into 5 groups: Current Officers, Past Presidents, Directors & Associate Directors, Members, Executive Board.
Easy to pull up and send emails only to one, two...or all 5 groups at once.
Adding people to MailChimp. Simply click add people and enter their info - make sure to select the groups that they belong to as well.