Remember the Milk, I couldn't help but sign up and try this free online task manager.
With the website's cute name, Remember the Milk helps you organize your tasks and categorize them into Personal, Study and Work lists. If you want more than a simple list, you could add more info about a certain task such as its due date, time estimate, location, or simply just add notes about it. There's also a color coding guide to label a task according to your priority.
Remember the Milk is not just for your computer alone. You can take your to-do list with you and be reminded via e-mail, SMS and instant messenger.
With a cool to-do list like that, who wouldn't forget the milk?
Free Travel Checklist
Free Online Task Manager
Free Birthdays & Events Reminder Tool
Other tools to help you keep organized: