Many seem to feel that somehow Al Gore would have "done something to stop it" by being all over airline security in a way that the Bush administration wasn't. However, when you look at Gore's actual history, the only time he had a hand in airline security, he apparently sold out for campaign contributions. (Link is down right now, but so is the site, so I hope it comes back).

And then there is that minority that thinks that somehow Bush or some other Western cabal (usually Israelis) actually planned and pulled it off. These people are nuts, and there's no point in arguing with them.

I agree that Gore would not have invaded Iraq. I don't know if he would have invaded Afghanistan either. Given the Clinton years as a precedent (admittedly a weak point to hang speculation on since Gore wasn't actually president) I speculate that he would have done some kind of heavy "Desert Fox" air attack on al Qaeda bases in Afghanistan and then gone home.