A true Method actor will not break character on set. They'll stay in character between takes, at the Craft Services table, etc. As mentioned, this is pretty rare these days.
Originally Posted by oink
Maybe somebody here can share some of the old horror stories of method acting of yesteryear?
I'll bet Josh has a lot of stuff in that movie encyclopedia in his head
he could share...
I can't think of any famous horror stories off the top of my head (though I'm sure some exist). In order to stay in character, most of these Method actors retreat to their trailers and isolate themselves as much as possible when they're not filming.