Interesting. Have you ever tried using the spaced repetition learning method by revisiting something in rapid succession, in many different places? I'd be interested to see how that compares to the standard method.
No; I don't have any metrics set up (Mnemosyne doesn't collect that sort of statistic) and by all accounts, the effect is fairly weak - nothing like spaced versus massed.
http://www.springerlink.com/content/m6lq80675m22232h/
There's probably some deep implications to this I'm not qualified to plumb. But next time I'm concentrating on something, and need to get up from the computer and walk around a bit, I'm going to try avoiding doorways.