I'm surprised that that I like coding on flights. It's surprising because airplanes are generally hostile environments for most things, but I've found it a good place to code.
The obvious reason is the lack of interruptions and distractions. Usualy there is no wifi, or it is too spotty to count on. So no email or IRC or web. While I know that distractions kill flow, I never seem give myself license to unplug in normal life. I'm a manager, and being a manager means being interruptible.
But there's another reason. When I code unplugged, I code differently. I have to be self-sufficient. Instead of just looking things up on StackOverflow, I take 20% more time to figure it out myself. That's much more satisfying! It's just not that hard to rummage through the Django code or try things out in iPython.
Also it just sounds cool to say you coded something up on the flight.
But thre real question is should simulate "airplane mode" when grounded. Hmm.