add visual cue and grab-buffer to priority of header tasks
Pre-pending an asterisk (*) to a task removes the check box from the Web UI. I've heard of this feature referred to as "header tasks." This feature is useful to me for creating ongoing "projects" (categories of tasks: care for your body, etc.) which capture categories of projects for sorting, and prospective projects (GTD "someday" items which need fleshing).
Check boxes themselves provide highly valuable visual cues. Color-coding with a task's priority is very useful in visually blocking out tasks for importance and sorting. While issuing keyboard commands (e.g.: "p", "s" to sort by priority), this gives strong confirmation on the sort change. The box is also useful as a UI buffer for dragging, or reorganizing tasks in the list, which gives a great user experience.
Removing the checkbox from "header tasks" is very useful for suppressing accidentally completing header tasks, providing an ideal container for the use-cases in the first paragraph; but the lack of visual cue loses the user interface benefits of the second paragraph. If both benefits could be realized at the same time, header tasks would be much more powerful.
I'd like to see a visual cue to the priority of a header task, and space for a user to mouse-grab a header task.
I tend to leave user experience implementation details to the UI designers closest to a product. I'm suggesting something along the lines of replacing the check box with some other shape (perhaps a circle, or some other visual which is differentiated from a checkable item), or fade-greying a colored box (indicating this is a task item, but can't be marked completed).