No idea about organitask but yes toodledo I had used long time back. But as of now I have been using hours tracking tool from Replicon ( http://www.replicon.com/olp/hours-tracking-software.aspx ). The cloud based tool featured with the calendar based and user friendly interface makes it an intuitive tool to manage the things set up in the right approach to line up a better business strategy.
OrganiTask sounds interesting, but doesn't look like its ready for primetime yet based on its documentation. If it supports multi-layer subtasks, I'll keep an eye on it. I'm also looking for a task manager that supports task dependencies.