Pretty nice way to find UIViewController of UIView using category

gistfile1.m

@interface UIView (FindUIViewController)

- (UIViewController *) firstAvailableUIViewController;
- (id) traverseResponderChainForUIViewController;

@end

@implementation UIView (FindUIViewController)

- (UIViewController *) firstAvailableUIViewController
{
    // convenience function for casting and to "mask" the recursive function
    return (UIViewController *)[self traverseResponderChainForUIViewController];
}

- (id) traverseResponderChainForUIViewController 
{
    id nextResponder = [self nextResponder];
    if ([nextResponder isKindOfClass:[UIViewController class]])
        return nextResponder;
    else if ([nextResponder isKindOfClass:[UIView class]])
        return [nextResponder traverseResponderChainForUIViewController];
    else
        return nil;
}

@end