Remember The Milk - Remember The Milk is a task and time management application for mobile devices.
Notepad Checklist - A checklist made by notepad.pw, easy short and fun to use.
TimePanic - TimePanic is an award-winning application for tracking time spent at the computer.
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
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.
Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.