Not a writer's retweet, either, though if you could spare one, I wouldn't say no... ;)
I'm about to embark on six days of intense solitude to - hopefully - finish outlining 'Some Kind of Angel', the sequel to 'Heaven Can Wait' (yes, before book 1 is available. I have reasons, but that's another post). By intense, I mean sort-of-intense. I'll be alone in my parents' house (I'm house-sitting for them while they're away looking after my grandma), but I'll have internet access and - doubtless - Twitter on non-stop. On the other hand, I'm not likely to speak to anyone face-to-face for longer than it takes me to go through a supermarket checkout (and even then, Asda have self-checkout now). The house next door is empty, too.
This is as close to a proper writer's retreat as I think I want to get. I have a book with me (book 3 of A Song of Ice and Fire), and my parents have a piano I'll probably play a lot, but other than that it's just me, my outlining notes, and the target of being in a position to start writing when I get back to Liverpool.
I'm actually a pretty solitary person by natural inclination, so this suits me rather well. I have at least one friend back in Liverpool who can't believe I won't go mad - and, in fairness, I expect to be talking to myself constantly by the time I leave, but I talk to myself readily anyway - but I won't have distractions (besides hunger etc.), I won't be going out to meet friends or play drums.
And I can cover every flat surface in the house with bits of paper filled with outlining notes. That's almost as important as the peace and quiet - my outline is spread over a dozen sheets of A3 paper at the moment, with a lot of detail still needing to be added, and in Liverpool I have to keep flipping back and forth between them, which is no mean feat with paper of that size. Now I can at least do the flipping by running around the place, rather than having to fold a broadsheet newspaper every time I want to check something.
I've had good experiences with writer's retreat-type breaks in the past. When I was sixteen, we holidayed in central Germany for a week where it was too hot to move most of the time, and I planned out five whole seasons of a tv show I was planning at the time (this was a fool's errand, but hey, I was 16, and you can't argue with the productivity). A couple of years back, we went to a cottage on the Isle of Skye in the Inner Hebrides, where there was no internet and little to do besides stare at (admittedly stunning) mountains all day, and I came back from that with a resurrected webcomic with a month's buffer, and planning notes for a series of novels I still hope to write some day.
I think it's the combination of solitude and targets that makes a retreat work for me - it produces a short, sharp burst of intense focus, and I work best in such bursts. I'm hoping that this retreat will get me through my outline so I can get back to the fun part - the writing. Detailed outlining is HARD WORK, but I can tell that 'Some Kind of Angel' has benefited immensely.