We've been discussing writer groups over at Jordan's blog, and I mentioned writer retreats as a working alternative to the annual org cons. I've been on a few private retreats and they were all good experiences -- got to hang with a good variety of writers, knocked out a lot of work, relaxed, talked about the reality of the biz, etc. Because they were private events we arranged ourselves, all we had to pay for was travel costs, hotel rooms and meals. Car pooling and sharing rooms helped keep those reasonable, too.
There are commercial writer retreat sites out there like this one that offer a variety of locations, services and pricing. I recommend getting in touch with a writer who's attended the retreat and asking some questions before committing.
Are there any commercial/non-commercial writer retreats you all know of that you can recommend for the working writers in need of a getaway/battery recharge? If you do, please post some info and any links you might have in comments.