I've spent a long time thinking about how best to design a UI with touch screen in mind. It feels like it ought to be a revolutionary new way of letting players interact with games, but so far I've not seen many examples of games really unlocking the full potential of touch screen.

As I see it, these are the main problems:

1. Fingers and thumbs blocking / getting in the way of the screen
2. Using movement (swipes & gestures) rather than poking buttons
3. Intuitive controls. Making gestures and touches do what the player thinks they ought to do
4. Screen real estate, (for mobile)

Anyone seen some good examples of games that use touch screen well, or have any tips / hints?