Fellow Windows Start Button Lovers, you are  not alone. Someone has created an application that allows you to restore the button back to Official Windows 8. Its called Start8 by Stardock.

Features

• Adds a Start menu to the Windows 8 Taskbar
• Enables quick access and searching of your installed applications
• Adds Run… option via right-click menu
• Adds Shutdown… option via right-click menu
• Choose a custom Start button image

Download here for version 0.86 which  works only on Windows 8 Consumer Preview or visit http://www.stardock.com/products/start8/ for further information.