Gmail Integrates Task List, Keeps You Organized

From here on, it's pretty straightforward. You can add tasks and reorder them, and of course, cross out the completed ones. But the killer feature is that Gmail Tasks allows you to convert emails into tasks, in a remotely similar way to Apple's Mail app on Mac OSX. In Gmail, you can select one or more messages, then go to More Actions > Add to Tasks and tasks are created out of your emails. For heavyweight users, keyboard shortcuts are also available.

However, Gmail Tasks is not yet a perfect feature. Even though you can add a due date for each task, this date doesn't get automatically added to your Google Calendar and no such option is available. Also, there isn't any option to share or email your tasks lists - like you can do with your calendars.

But if you're into hardcore task lists, and Gmail Tasks is too lightweight for your needs, then you can always check Remember the Milk. This service supports Google Gears (and can work offline) and integrates with your Gmail Inbox via Gadgets, giving you searchable tasks, Google Calendar syncing, to-do tags and even mapping of your next to-do's location. As a bonus, Remember the Milk also has a free application for Apple's iPhone.