Exclusive Lifehacker Download For Windows: Navigate backward and forward with Rocker - Lifehacker
Basically what it does is add another click format, like right clicking.
Rocking is holding one mouse button down and then clicking the other one.
For example rocking to the right would mean clicking and holding your left mouse buton and then without letting go clicking your right button.
Why might you use it? It's works on your internet and stuff, rock to the right to go forward, rock to the left to go backwards.
I just installed it today and it's really useful! Best of all it's free and developed by a hacker