I consider myself a normal user, and I am always adding tasks (Ideally no more often than I am completing them :)). Why do I need to click "Add a Task" way up in the corner each time I need to do this? Why not (at least optionally) have the task entry form always open? I know this is not as pretty for some, but it is a much more functional, fast UI this way.
You can quickly press the 'n' key anywhere on the page for the add task panel to show up. Also, if you use Firefox (it's a sin to use any other browser anyway), you can install their Firefox add-on, using which you should be able to add a task from any website/page by pressing Ctrl. + Alt. + A
A few other cloud-based task management solutions have a "quick add" field always in view, although you still need to click in it to start typing and as piyush_soni said, pressing 'N" will allow you to do the same thing anyway.