Best practice for duration and animationCurve for flip animations on iPhone (UIViewAnimationTransitionFlipFromRIght)?

Sometimes I use a flip animation on the iPhone, and I play with it until I get the animation duration to feel right.

Is there any definite values, or arguments for values, that I should be using to set the duration or curve of the anima开发者_如何转开发tion?

Is there any reason you need to set the duration at all? If you use the standard [UIView beginAnimations:nil context:nil] it will already have a duration set up of 0.25 seconds.

The keyboard appear/disappear duration is also .25, so that is probably number Apple uses consistently for a consistent user experience.