Wow, awesome thread, thanks for making everything so clear and simple. Also thanks for your other versus threads, I always wondered if Umbra was really the strongest and what kind of arrows I should look for. I hope to see more awesome stuff from you but it looks like you complitly covered oblivion already
Another good way to level Sneak very quickly is to go to the Skooma Den in Bravil. Once inside, you can pickpocket the NPCs who live there since they have a Responsibility of 0 and won't report any crimes (except for Roxanne Brigette and any of the weekly visitors). Even if you don't actually steal anything, mereley entering and leaving the pickpocketing screen will give you 2 xp. each time you do it. I recommend doing this instead of sneaking around for hours on end (every second undetected gives you 0.75xp, but pickpocketing would give you around 2 xp per second; you just have to get the timing right). Oh, one last thing, do NOT let the visitors or Roxanne Brigette spot you pickpocketing because they WILL call the guards.