Also - make sure you've got a nice view. We've found that our productivity increases substantially when we've got something nice to look at. Building product in basements is depressing and can really drain your energy/creativity/purpose. There's something about the ocean or the desert that can really drive you forward.
Though as far as i understood, they solved this with going out as tourists only on weekends.
Except it never happens. Seems my motivation / drive is so depleted that the best way to use the days off is to actually rest. Then I feel great (although generally a little miffed that I didn't get anything done on project X) and for the next several weeks I seem to have more focus and be able to get my everyday things done more effectively.
Sometimes the best way to utilise a break is exactly that - have a (complete) break and just rest the mind - I find some physical exercise (surfing) helpful with that too.
Again GTD is a good way to make your way through work.
Also: when you're on the road, you won't need to go and see family and friends. You'll miss them. But a lot of time is free to do other stuff.