While I agree with their conclusion, I disagree with their argument. Penn and Teller are equating the word "militia" with the modern "military". This is an incorrect comparison. The old definition of "militia" was, "the body of all able-bodied men, trained in arms." This was differentiated from the "standing army" which we now call "the military". When the 2nd Amendment refers to to "the militia" and "the people", it is essentially referring to the same thing.
A "well-regulated" militia meant a "properly function" militia, back in the day. It does not mean "regulation by law", as the proponents of big governement would like you to believe.
Some the 2A is actually saying, "Since an armed body of citizens is necessary to keep a fee nation, the right of those citizens to own and carry arms shall not be infringed." It is implied that the armed citizenry is expected to counterbalance the government's standing army.
I agree with Penn and Teller's defense of the 2nd Amendment, but I think they are a little off with the facts.
i love penn and teller. i may not agree 100% with everything they stay, but dag gone it, were are rocking a 95% at least agreement rating. i am really surprised they have not had an "accident" during one of their shows.