I have used omnifocus for a pretty long time now (1.5 years or so) and when I recently carried out a review of how my system was setup I noticed that even though I tagged everything with contexts, I rarely used these.
I decided to change my contexts so that they better reflected what I actually, rather than, @computer, @home, etc.
So this is my updated list and after a week of use I must say I like it better.
I am thinking of finding a better way of managing develop, maintenance, fix & tinker. Common for these three is that I actively carry something out with some sort of endresult which is not paperwork, for example.
Maybe something like DO -> develop, maintenance, fix & tinker would be a working setup.

@email @phone @errands @fix & tinker @clean @research & review @relax@management with subcategories @staff @strategy @planning@paperwork with subcategories @online @invoice @print @letters @pay @bookkeeping@develop with subcategory maintenance
my @waiting category has many subcategories has got subcategories for each person I often wait for, but I will keep these a secret :)I can however tell that one of the subcategories is called @apple :)

David Rinnan
http://www.google.com/profiles/david.rinnan