Anyway, the snake/frog/snail thing is right. I read an interview with the guy, whose name escapes me, who writes Naruto and he says the snail, the frog and the snake are like a "paper, scissors, rock" type deal in japanese mythology.

So I guess that means that each of the 3 sannin are supposed to be defeatable by one of the others. So that probably means that, while Jir can beat or at least tie Itachi, he would probably lose to one of the other Sannin(whichever one the mythology says frog loses to), but the sannin that could beat Jir probably couldn't beat Itachi.

I wonder if, since Naruto knows frog summoning, if Sasuke will learn to summon snakes and Sakura snails.