A basic nine-grid sprite node for Cocos2D. You set the contentSize property of the sprite and it will do the layout automatically. The layout also respects the anchorPoint property so it's easy to align the sprites however you want.

Example.m

CCSprite *sprite = [CCSprite spriteWithFile:@"button9grid.png"];
NGNineGridSprite *nineGrid = [NGNineGridSprite spriteWithSpriteFrame:sprite.displayFrame andCornerSize:CGSizeMake(10, 10)];
nineGrid.position = ccp(160, 240);
nineGrid.anchorPoint = ccp(0.5, 0.5);
nineGrid.contentSize = CGSizeMake(150, 150);
[self addChild:nineGrid];

NGNineGridSprite.h

//
//  NGNineGridSprite.h
//  Created by Nick Gravelyn
//
//  Distributed under terms of MIT License:
//  http://www.opensource.org/licenses/mit-license.php
//

#import <Foundation/Foundation.h>
#import "cocos2d.h"

@interface NGNineGridSprite : CCNode 

- (id)initWithSpriteFrame:(CCSpriteFrame *)frame andCornerSize:(CGSize)cornerSize;
+ (NGNineGridSprite *)spriteWithSpriteFrame:(CCSpriteFrame *)frame andCornerSize:(CGSize)cornerSize;

@end

NGNineGridSprite.m

//
//  NGNineGridSprite.m
//  Created by Nick Gravelyn
//
//  Distributed under terms of MIT License:
//  http://www.opensource.org/licenses/mit-license.php
//

#import "NGNineGridSprite.h"

@interface NGNineGridSprite ()
{
    CGSize _contentSize;
    CGSize _cornerSize;
    
    CCSprite *corners[4];
    CCSprite *horizontalEdges[2];
    CCSprite *verticalEdges[2];
    CCSprite *center;
}
- (void)updateChildScales;
- (void)updateChildPositions;
@end

@implementation NGNineGridSprite

- (id)initWithSpriteFrame:(CCSpriteFrame *)frame andCornerSize:(CGSize)cornerSize
{
    if (self = [super init])
    {
        _contentSize = CGSizeMake(0, 0);
        _cornerSize = cornerSize;
        
        // we're going to put all the pieces into a batch node so all 9 pieces are drawn at once
        CCSpriteBatchNode *batchNode = [CCSpriteBatchNode batchNodeWithTexture:frame.texture capacity:9];
        [self addChild:batchNode];
        
        // temporary rect variable used all over during construction
        CGRect tempRect;
        
        // create the four corner sprites
        tempRect = CGRectMake(frame.rect.origin.x, frame.rect.origin.y, cornerSize.width, cornerSize.height);
        corners[0] = [CCSprite spriteWithTexture:frame.texture rect:tempRect];
        corners[0].anchorPoint = ccp(0, 1);
        corners[0].position = ccp(0, frame.rect.size.height);
        [batchNode addChild:corners[0]];
        
        tempRect.origin = CGPointMake(frame.rect.origin.x + frame.rect.size.width - cornerSize.width, 
                                      frame.rect.origin.y);
        corners[1] = [CCSprite spriteWithTexture:frame.texture rect:tempRect];
        corners[1].anchorPoint = ccp(1, 1);
        corners[1].position = ccp(frame.rect.size.width, frame.rect.size.height);
        [batchNode addChild:corners[1]];
        
        tempRect.origin = CGPointMake(frame.rect.origin.x, 
                                      frame.rect.origin.y + frame.rect.size.height - cornerSize.height);
        corners[2] = [CCSprite spriteWithTexture:frame.texture rect:tempRect];
        corners[2].anchorPoint = ccp(0, 0);
        corners[2].position = ccp(0, 0);
        [batchNode addChild:corners[2]];
        
        tempRect.origin = CGPointMake(frame.rect.origin.x + frame.rect.size.width - cornerSize.width, 
                                      frame.rect.origin.y + frame.rect.size.height - cornerSize.height);
        corners[3] = [CCSprite spriteWithTexture:frame.texture rect:tempRect];
        corners[3].anchorPoint = ccp(1, 0);
        corners[3].position = ccp(frame.rect.size.width, 0);
        [batchNode addChild:corners[3]];
        
        // create the horizontal edges
        tempRect = CGRectMake(frame.rect.origin.x + cornerSize.width, frame.rect.origin.y,
                              frame.rect.size.width - (cornerSize.width * 2), cornerSize.height);
        horizontalEdges[0] = [CCSprite spriteWithTexture:frame.texture rect:tempRect];
        horizontalEdges[0].anchorPoint = ccp(0, 1);
        horizontalEdges[0].position = ccp(cornerSize.width, frame.rect.size.height);
        [batchNode addChild:horizontalEdges[0]];
        
        tempRect.origin = CGPointMake(frame.rect.origin.x + cornerSize.width, frame.rect.origin.y + frame.rect.size.height - cornerSize.height);
        horizontalEdges[1] = [CCSprite spriteWithTexture:frame.texture rect:tempRect];
        horizontalEdges[1].anchorPoint = ccp(0, 0);
        horizontalEdges[1].position = ccp(cornerSize.width, 0);
        [batchNode addChild:horizontalEdges[1]];
        
        // create the vertical edges
        tempRect = CGRectMake(frame.rect.origin.x, frame.rect.origin.y + cornerSize.height,
                              cornerSize.width, frame.rect.size.height - (cornerSize.height * 2));
        verticalEdges[0] = [CCSprite spriteWithTexture:frame.texture rect:tempRect];
        verticalEdges[0].anchorPoint = ccp(0, 0);
        verticalEdges[0].position = ccp(0, cornerSize.height);
        [batchNode addChild:verticalEdges[0]];
        
        tempRect.origin = CGPointMake(frame.rect.origin.x + frame.rect.size.width - cornerSize.width, frame.rect.origin.y + cornerSize.height);
        verticalEdges[1] = [CCSprite spriteWithTexture:frame.texture rect:tempRect];
        verticalEdges[1].anchorPoint = ccp(1, 0);
        verticalEdges[1].position = ccp(frame.rect.size.width, cornerSize.height);
        [batchNode addChild:verticalEdges[1]];
        
        // create the center
        tempRect = CGRectMake(frame.rect.origin.x + cornerSize.width, frame.rect.origin.y + cornerSize.height,
                              frame.rect.size.width - (cornerSize.width * 2), frame.rect.size.height - (cornerSize.height * 2));
        center = [CCSprite spriteWithTexture:frame.texture rect:tempRect];
        center.anchorPoint = ccp(0, 0);
        center.position = ccp(cornerSize.width, cornerSize.height);
        [batchNode addChild:center];
        
        // set up default size which handles all scaling and positioning of the sprites
        self.contentSize = frame.rect.size;
    }
    return self;
}

- (void)setContentSize:(CGSize)contentSize
{
    // always maintain integer size
    contentSize.width = roundf(contentSize.width);
    contentSize.height = roundf(contentSize.height);
    
    // if the content size is different, store it and update both scale and position of children
    if (_contentSize.width != contentSize.width || _contentSize.height != contentSize.height)
    {
        _contentSize = contentSize;
        [self updateChildScales];
        [self updateChildPositions];
    }
}

- (CGSize)contentSize
{
    return _contentSize;
}

- (void)setAnchorPoint:(CGPoint)anchorPoint
{
    // get the old anchor point
    CGPoint oldAnchorPoint = self.anchorPoint;
    
    // if anchor point changed, store it and update position of children
    if (oldAnchorPoint.x != anchorPoint.x || oldAnchorPoint.y != anchorPoint.y)
    {
        [super setAnchorPoint:anchorPoint];
        [self updateChildPositions];
    }
}

- (void)updateChildScales
{
    // adjust the width to account for corners
    int adjustedWidth = _contentSize.width - (_cornerSize.width * 2);
    
    // adjust the X scale of the horizontal edges and center
    horizontalEdges[0].scaleX = adjustedWidth / horizontalEdges[0].contentSize.width;
    horizontalEdges[1].scaleX = adjustedWidth / horizontalEdges[1].contentSize.width;
    center.scaleX = adjustedWidth / center.contentSize.width;
    
    
    // adjust the height to account for corners
    int adjustedHeight = _contentSize.height - (_cornerSize.height * 2);
    
    // adjust the Y scale of the vertical edges and center
    verticalEdges[0].scaleY = adjustedHeight / verticalEdges[0].contentSize.height;
    verticalEdges[1].scaleY = adjustedHeight / verticalEdges[1].contentSize.height;
    center.scaleY = adjustedHeight / center.contentSize.height;
}

- (void)updateChildPositions
{
    // use the anchor to adjust all positions
    CGPoint anchorShift = CGPointMake(-self.anchorPoint.x * _contentSize.width, -self.anchorPoint.y * _contentSize.height);
    
    // update all the corners
    corners[0].position = ccpAdd(ccp(0, _contentSize.height), anchorShift);
    corners[1].position = ccpAdd(ccp(_contentSize.width, _contentSize.height), anchorShift);
    corners[2].position = ccpAdd(ccp(0, 0), anchorShift);
    corners[3].position = ccpAdd(ccp(_contentSize.width, 0), anchorShift);
    
    // update the horizontal edges
    horizontalEdges[0].position = ccpAdd(ccp(_cornerSize.width, _contentSize.height), anchorShift);
    horizontalEdges[1].position = ccpAdd(ccp(_cornerSize.width, 0), anchorShift);
    
    // update the vertical edges
    verticalEdges[0].position = ccpAdd(ccp(0, _cornerSize.height), anchorShift);
    verticalEdges[1].position = ccpAdd(ccp(_contentSize.width, _cornerSize.height), anchorShift);
    
    // update the center
    center.position = ccpAdd(ccp(_cornerSize.width, _cornerSize.height), anchorShift);
}

+ (NGNineGridSprite *)spriteWithSpriteFrame:(CCSpriteFrame *)frame andCornerSize:(CGSize)cornerSize
{
    return [[[NGNineGridSprite alloc] initWithSpriteFrame:frame andCornerSize:cornerSize] autorelease];
}

@end