RTM allows you to create various lists so you can separate your to-do lists. The default is personal, work, and study but you can create more in the settings section.
This is a 23 Things List showing the different weeks as individual tasks. Details of the different tasks are in the notes section and the tasks have been tagged with the initials of the people doing them so we can search for our own tasks:
It is possible to add a location to a task and these are linked to Google Maps so you can view them all on a map. You have to create the location before you can use it but once it is created you can keep using it.
To set up an account go to: http://www.rememberthemilk.com/.