Where can I buy Westvleteren beer?

Last weekend in Amsterdam I had what might be my new favorite beer.  It’s a Belgian Trappist production, Westvleteren.  Our friends Pascale (who’s Belgian) and Maria served us some at their home, noting it was difficulty to obtain even in the beer capitals of Europe.

Does anyone know if there’s a place in or around Boston where I can buy a case?  I see some stuff online via Google Product Search, but shipping alcoholo to Massachusetts is a challenge.
I had their Blonde, but I’d be happy to try the two other varietals as well, naturally.