Here is an amateur commercial that I think takes a very effective shot at that terrible, terrible ticket.
It makes three points:
(i) Governor Palin is pretty rotten.
(ii) She is rotten not because of her inexperience, or her kids, or her reproductive history, or any of that Peyton Place stuff, but because she has radical, extreme views.
(iii) This is bad news for John McCain, because he chose her as his soulmate.
(Youtube link; h/t Boingboing.)
For what it's worth, this is a point that I have argued previously: Palin is very useful to us, because she is a whacko, and McCain chose her to be the leader of the free world in the event that he has a stroke. He has demonstrated for all the world what kind of decisions he makes (not as if he hasn't done that before, especially with the Iraq war, but this is wrapped up in a little bow for us). The right-wing of the Republican party think this is great, but I don't think that independent voters will be thrilled with the quality of thinking on display here.
My though: Palin needs to be used, as a club, against Mr. McCain. I think this ad does it very well.