How do I go about figuring out how fast someone swiped on the iphone? Any example?
Do I use Touch.deltatime? Whats deltaPosition do?
Thanks in advance.
Take a look at the Unity reference manual on what deltaPosition does.
A quick search of Unity Answers revealed your question asked many times. Here is the first answer that matches your question.
http://answers.unity3d.com/questions/5288/iphone-how-to-calculate-a-decent-touch-swipe-speed