What email client do you use?
vulpes: Surprised there isn't any votes for Postbox app (http://getpostbox.com).  * It integrates well with gmail 
  * does great with multiple accounts 
  * multiple outgoing addresses 
  * great search functionality 
  * GTD tools such as assigning emails a topic. 
  * Integration with facebook/twitter to pull up contact info 
  * Extensions such as calendar and contacts

Based on thunderbird, all around awesome client.