Customizing G+1 button using CSS Mask
Social media buttons are getting harder and harder to customize. As the buttons obtain more functionality along with complexity you want to preserve the bonuses but still get enough customization to fit your project.
Edan Kwan has a real nice tutorial for applying subtle customization to the +1 button. This does not show you how to replace the button, only how to customize the shape and maintain function.
p.s. image available here in vector download