mobile programming questions

There is a stationary phase with the touch class.

http://unity3d.com/support/documentation/ScriptReference/TouchPhase.html

So:

 void Update()
         {
             if( Input.touchCount == 1 )
             {
                 Touch touch_0 = Input.touches[0];
                 
                 switch( touch_0.phase )
                 {
                 case TouchPhase.Stationary:
                     //Do checks here
                     break;
                 default:
                     break;
                 }
             }
         }