Detect backspace in UITextField

Is there any way to detect when the backspace/delete key is pressed in the iPhone keyboard on a UITextField that is empty?
Here is non-hacky and very simple with a quick subclass of UITextField.
This is the best solution. Objective C is based on sub classing and this solution uses it properly to solve the problem.
Sadly, this only works for >= iOS 6 though

//Header
//MyTextField.h

//create delegate protocol
@protocol MyTextFieldDelegate <NSObject>
@optional
- (void)textFieldDidDelete;
@end

@interface MyTextField : UITextField<UIKeyInput>

//create "myDelegate"
@property (nonatomic, assign) id<MyTextFieldDelegate> myDelegate;
@end

//Implementation
#import "MyTextField.h"

@implementation MyTextField

- (void)deleteBackward {
    [super deleteBackward];

    if ([_myDelegate respondsToSelector:@selector(textFieldDidDelete)]) [_myDelegate textFieldDidDelete];
}

@end

//View Controller Header
#import "MyTextField.h"

//add "MyTextFieldDelegate" to you view controller
@interface ViewController : UIViewController <MyTextFieldDelegate>
@end

Now simply add "MyTextFieldDelegate" to your ViewController and set your textfields "myDelegate" to "self":

//View Controller Implementation
- (void)viewDidLoad {
    //initialize your text field
    MyTextField *input = [[MyTextField alloc] initWithFrame:CGRectMake(0, 0, 70, 30)];

    //set your view controller as "myDelegate"
    input.myDelegate = self;

    //add your text field to the view
    [self.view addSubview:input];
}

//MyTextField Delegate
- (void)textFieldDidDelete {
    NSLog(@"delete");
}