One important productivity tip whether it be in the physical or virtual worlds is to avoid clutter.
Ever notice how a cluttered desk or office space can cause stress? You may not realize it till you clean up and then realize, "Wow, I feel so much better now". Whether you consciously realize it or not, clutter distracts you in a variety of ways and none of them are good.
Concept is simple, this little baby removes the ad clutter from your GMail, Hotmail and Yahoo email screen. Below is a real life example from my Gmail earlier today with Webmail Ad Blocker off and then with it on. I've been using this for over a year and have not had any problems with it.
Now you can stay focused on the task at hand. Less clutter. Less chance of being distracted by an ad and running off down a time-wasting rabbit-hole!