I've often found myself a more convenient way to add a simple barButtonItem to a navigation or tool bar, so I created this nice little subclass.

SLBarButtonItem.h

#import <UIKit/UIKit.h>

@class SLBarButtonItem;

typedef void (^SLBarButtonItemCompletionBlock)(SLBarButtonItem *sender);

@interface SLBarButtonItem : UIBarButtonItem

+(SLBarButtonItem *)barButtonSystemItem:(UIBarButtonSystemItem)systemItem;
+(SLBarButtonItem *)barButtonWithTitle:(NSString *)title style:(UIBarButtonItemStyle)style;
+(SLBarButtonItem *)barButtonWithImage:(UIImage *)image style:(UIBarButtonItemStyle)style;
+(SLBarButtonItem *)barButtonWithImage:(UIImage *)image landscapeImagePhone:(UIImage *)landscapeImagePhone style:(UIBarButtonItemStyle)style;

@property (nonatomic, copy) SLBarButtonItemCompletionBlock completionBlock;

@end

SLBarButtonItem.m

#import "SLBarButtonItem.h"

@implementation SLBarButtonItem

-(void)actionForBarButtonItem
{
	if (_completionBlock)
		_completionBlock(self);
}

+(SLBarButtonItem *)barButtonWithImage:(UIImage *)image style:(UIBarButtonItemStyle)style
{
	SLBarButtonItem *item = [[SLBarButtonItem alloc] initWithImage:image style:style target:nil action:nil];
	item.target = item;
	item.action = @selector(actionForBarButtonItem);
	return item;
}

+(SLBarButtonItem *)barButtonWithTitle:(NSString *)title style:(UIBarButtonItemStyle)style
{
	SLBarButtonItem *item = [[SLBarButtonItem alloc] initWithTitle:title style:style target:nil action:nil];
	item.target = item;
	item.action = @selector(actionForBarButtonItem);
	return item;
}

+(SLBarButtonItem *)barButtonWithImage:(UIImage *)image landscapeImagePhone:(UIImage *)landscapeImagePhone style:(UIBarButtonItemStyle)style
{
	SLBarButtonItem *item = [[SLBarButtonItem alloc] initWithImage:image landscapeImagePhone:landscapeImagePhone style:style target:nil action:nil];
	item.target = item;
	item.action = @selector(actionForBarButtonItem);
	return item;
}

+(SLBarButtonItem *)barButtonSystemItem:(UIBarButtonSystemItem)systemItem
{
	SLBarButtonItem *item = [[SLBarButtonItem alloc] initWithBarButtonSystemItem:systemItem target:nil action:nil];
	item.target = item;
	item.action = @selector(actionForBarButtonItem);
	return item;
}

@end