Compose emails and documents out of frequently used text blocks. You can run any number of follow-up actions each time you copy a snippet. For example, you could add a row to a spreadsheet (.tsv and .csv) with the name and email address of whom you replied to and set a reminder for yourself to follow up with that person after a week.
Mia for Gmail (was Notifier Pro for Gmail) is a desktop Gmail client which sits politely in your menu bar.
