I posted some time ago about visual to-do list. I had found that listhings was not a bad website, but sadly it was not fully functional on iPad. Today while I was poking around online I found Spaaze. It has more functionality, and works on my iPad!
It's beta right now, and free. They list 2 possible pricing structures. One is wanky points system which looks geared to nickel and dime you to death. There is also a straight out subscription which seems more reasonable.
And no, I am not the developer or anything.