New Gmail Lab Feature: Suggest more recipients
Here's another Gmail lab feature you may find useful:
Gmail will suggest people you might want to include based on the groups of people you email most often. So if you always email your mom, dad, and sister together, and you start composing a message to your mom and dad, Gmail will suggest adding your sister. Enter at least two recipients and any suggestions will show up like this:Click on a suggested name, and they'll get added to your email.