Todoist is an online todo or task list utility. I tried several such sites because I wanted something I could access from my laptop or desktop without having to sync the two. I also like knowing it’s backed up elsewhere.
There are several additional features that makes Todoist really useful: gmail intergration, plugins for Launchy and Quicksilver and helpful keyboard shortcuts too. You can sort the list by due dates, context and project. If you try it out be sure to watch the tutorials to see how to use extra features, they are all simple but not obvious.
Here are a couple of other reviews:
http://www.readwriteweb.com/archives/todoist_task_management.php