Using a bit of CSS magic, designer Fabio Giolito has created a theme that turns Google+ into a dead-ringer for Facebook. The theme is installable as a userstyle user script or as an add-on for the Chrome/Firefox plugin Stylish. Internet Explorer and Opera users can also install the script, which alters the design of Google+ to mimic the colors and layout of Facebook.
Check out the before and after images to see Google+ Facebook in action. Fabio has also put the code for the userstyle on Github.