MailContacts scans through your e-mails and presents you with all the contacts you interacted with. In addition, the application allows you to add the addresses missing within your address list with just a click. It even summarizes similar addresses and differentiates between unknown contacts and the ones that are already in your address book.
Mia for Gmail (was Notifier Pro for Gmail) is a desktop Gmail client which sits politely in your menu bar.
