The MailFollowUp bundle adds a "Follow Up" item to the Message and contextual menus (and optional toolbar item) of Apple's Mail application that allows you to compose (and then send) a quoted version of the original message to all of the original recipients, keeping the To, CC, and BCC addresses exactly as they appeared in the original message.
Mia for Gmail (was Notifier Pro for Gmail) is a desktop Gmail client which sits politely in your menu bar.
