Travelling from LAS to PHX, I was recently confronted with a passenger who stood in the exit row and held out his arms to indicate that he was 'saving' all of the exit row seats for his companions....all 11 of them. I looked at him increduously and sat down in my favorite seat....the one with no seat in front of it. He was not amused but the FA did tell him that he wasn't going to be able to do that. I'm with the poster who says "pay the extra $10" or go home.