First of all thanks to all who responded!
Now, let's see what we have got here...
1. mental contexts - do group items that require the same mindset. Nice in theory, but only partly so in praxis. Sometimes the mental context is the project or even some higherlevel stuff... But even so, workable it seems...
... yeah, I think I can see that
2. Katherine transcents the mental "contexts" even above the semi-physical ones
3. Ruud points out that mental states and energy levels seem to be related
4. by eckbeerg: "I guess the question is where are your hard edges when it comes to computer usage?" Yes, the hard edges. Email seems to be one of them for me, but other than that... see also why these also can be viewed as bad computer setup
http://www.winterspeak.com/columns/082001.html (specially the 'good easy).
6. Sorting a context list by urgency. And the warning to not loose the ability to review one's list based on context when adding such further dimension.
7. Nobody thinks sorting by total time needed to accomplish is a cool idea.
So, what's the next action?
Observing myself to find out where my real computer-based hard edges are.
From a mailing list: "A context is some restraint that only allows the action to be done in a particular place, time, or with particular resources."
The only thing that changes here is "time" for IM and "particular resources" for states inside my head. Energy? And offcourse "time" until the next appointment, the hard landscape.
Maybe it is best to routinely schedule actions from one type of work...
I dunno.