Lizard had a great post years ago that touched on the idea of an "out the door" context:
http://forums.omnigroup.com/showthread.php?t=8992
Seems to me like it is a very similar notion to yours.
Are you using the iPhone app? If you have locations assigned to your contexts, you could do something similar to what you propose. Leaving work, you pull up the Map display, find the first context listed that you're interested in visiting, get directions there and tackle the actions available when you arrive. Repeat until you run out of time, actions, or money, then drive home.