I wrote up this post (Reddit.com) on useful tips/tricks using an iPad 2 with iOS 5. Thought some tested people might like it :)
Also, I would love if a tested writer made a post with some tips/tricks that even I haven't picked up yet. Some of them aren't intuitive and you really would have no idea they were there unless someone showed you, i.e. tap and hold on the new tab button in Safari to get a recently closed tabs list. Like Will has said, iOS 5 was the most confusing update ever, with no heads up for users saying, "Hey, here are the new features and here's how to use them!"