I have to rotate a view circularly on finger touch...I mean like dialing the old phones number...and the touch should be only on corners.....can any one help me...i have tri
You need to define the UIRotationGestureRecognize on the view that you want to rotate and than add a selector method and implement it like this.
Add this to you viewDidLoad method 
UIRotationGestureRecognizer *rotate = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotation:)];
[myUIViewObject addGestureRecognizer:rotate];
[rotate release];
And then implement the method.
- (void) rotation:(UIRotationGestureRecognize *) sender
{
    CGAffineTransform myTransform = CGAffineTransformMakeRotation(sender.rotation);
    sender.view.transform = myTransform;
}
PS. myUIViewObject can be any UIView Object that you want to rotate.
Edit:
you will find a lot of information on this here:
http://www.iphonedevsdk.com/forum/iphone-sdk-development/49847-how-find-angle-two-points.html