Commandline Challenge - Test your command line skills
Toggl - Toggl is an online time tracking tool. It features 1-click time tracking and helps you see where your time goes. Free and paid versions are available.
Prompt - Prompt provides fully-integrated writing education solutions, combining instruction, curriculum, and feedback. We support educational institutions, companies, and individuals.
Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.
Cwiki - A Command line interface for searching Wikipedia!
RescueTime - Time management software that shows you how you spend your time & provides tools to help you be more productive.