This Mod has been out now for a little while. Somehow I missed it. I am sure a few of you may have missed it as well so I decided to go ahead and share it. Everyone has had a friend ask to borrow your phone. What if you have some private info that you would rather your friend not run across. You can't simply deny your friend. You just have to hand it over and take the risk. Not anymore. Developer Zanderman112 has discovered a very simple hack to enable multiple user accounts on phones that are running 4.1 or higher. You will need to be rooted and you will need to have terminal emulator installed on your phone.
In terminal emulator type
pm create-user guest
"guest" could be anything, your girlfriends name, your favorite team whatever.
Then hold the power menu to bring up the power settings and you will see a second user account. If you select this you will be prompted to set up your phone like it is new. You can easily toggle back and forth between accounts. To delete the second account you just enter terminal emulator and type su, then type pm remove-user 1. If this is too much hackery for you there has also been an application that has been created that does the same thing!