http://www.iphonedevsdk.com/forum/iphone-sdk-development/6573-howto-customize-uikeyboard.html?0f266420

http://cocoawithlove.com/2009/04/showing-message-over-iphone-keyboard.html

http://www.iphonedevsdk.com/forum/iphone-sdk-tutorials/7350-adding-subviews-custimize-keyboard.html

http://www.ipodtouchfans.com/forums/archive/index.php/t-176944.html

http://www.ipodtouchfans.com/forums/archive/index.php/t-173786.html

http://www.ipodtouchfans.com/forums/archive/index.php/t-168191.html