title: How to track NSTouches?
body: <p>I'm building a game and this is the first time where I've needed more than one touch to work. I've noticed that there appears to be no rhyme or reason to the indexing of touches in the NSSet. It can even flip while both touches are still active. Can anyone explain this? And can anyone explain how I can keep track of each touch and it's movements (since asking for the touch at an index may not return the one you thought was there)?</p>