If you use the GTD technique, then you may be interested in an online service vitalist.com . Just like in most GTD systems, there is a division into Actions, Waiting, Projects, etc. There is no serious waste from David Allen's methodology. Unlike some of its competitors, vitalist provides a simple (if not primitive) contact management system.
I really liked the vitalist interface, everything is simple and convenient. The undoubted advantage of the service is the ability to work using mobile devices — a special version is provided for this, available at www.vitalist.mobi . Actions can be added using the web interface or by sending them by email. Another option that I really didn't have time to try is adding voice actions (you need to call a special number and dictate them).
In vitalist, you can export all tasks and plans in RSS and iCal format (calendar in Mac OS). The service is able to send notifications by e-mail and to the phone (with Beeline, however, it did not work).
There are two tariff plans. In my opinion, the differences between free and commercial are not so serious — you will not be able to attach files to actions, SSL will not be used in work, you cannot open access to your contexts and projects to other users, you will have to watch advertising (while there is no advertising).
In my opinion, vitalist is one of the best online GTD implementations. And what do you use?
