Everyone with whom I've spoken on this matter seems to thing that it's impossible, but I know that it can be done in many other platforms (eCircle and Marketo for example). What I'd like to do is this:
Have a data extension with say first, last name, email address, and then some arbitrary field. This field I would like to be able to use to create and sort reports. So for example if my field was 'city' and I had 4 cities to choose from: Boston, Chicago, Raleigh, Tulsa. I would like to be able to send an email to this DE and later create a report with basic information like number of opens from Raleigh, or CTR from Tulsa. This seems like pretty basic functionality but I can't seem to find any information on it?