Stay Focused Online

Focus Booster is a pomodoro technique online software timer

Your time is too valuable to waste. For the cost of two lattes, Freedom will help you fight evil distractions so you can get your work done.

Although created to protect your eyesight, this is a great tool to remind you to take a break from the computer.

LeechBlock is a simple productivity tool: an
extension for the
Firefox web browser designed to
block those time-wasting sites that can suck the life out of your
working day. (You know: the ones that rhyme with "Blue Cube", "Space
Hook", "Sticky Media", "Quitter", and the like.) All you need to do is
specify which sites to block and when to block them.

An online task-by-task to-do list that will keep you focused on one thing at a time.

Free Mac application to help you avoid distracting websites.

A personal-analytics service that shows you how you spend your time & provides tools to help you be more productive.