I like the: Are-you-really-sure-approach a lot. There is quite some potential there. Pair this with an occasional laughter, some head shaking, add "uh, that makes it easy" once in a while and give an Al Gore impression (during the first debate, for those of you that are politically interested).
Oh, and a good one too, when playing with Newbies, the: Uh-i-forgot-to-mention-that-rule approach. (I've seen this work through the newbies point of view). If you are convincing enough, you don't even have to be right

-> No, you can't score with a linemen in turn 5 on a Wednesday night, unless it is your birthday (you might want to do it less obvious, then leave a little through the rulebook and then claim it is mentioned somewhere, but you can't find it right now).