Canned Responses is the latest mod from the GMail Labs. If you find yourself writing the same email messages over and over again, this mod will make your life a whole lot easier.
Instead of copy/pasting from text files, canned Responses lets you quickly insert template text messages from a list of messages that you can pre-define. You can use it for frequently repeated queries, acceptance/rejection emails, campaigns or anything else that suits your needs.
If you are an internet power-user / info-maniac, chances are that you use Firefox as your primary browser, and if you have been a Firefox user for a few months, your have undoubtedly installed a bunch of add-ons and plugins that are now a part of your life. These Add-ons are constantly vying for screen real estate and leaving you on the constant lookout to use the few million precious pixels on your screen(s) more effectively.