The Compaq CQ56 models have been discontinued but you can get some good buys because of that.
The HP G6 Pavilion series is currently available from Amazon and you can read user reviews to help you pick a model in your price range.
the iPad2 is a great device, extremely portable but for taking notes it may not be the easiest unless you also carry around a bluetooth keyboard.
All the machines will be good for music, pictures, internet and some games. You should think more about size, weight, price and warranty rather than the specification for a machine with such simple tasks.