No, it’s not really as cool as it sounds, but it’ll still come in handy if you’re administrator of multiple Facebook pages like I am. It’s called the voice option, and it’s located up near your name in the upper-right corner of your screen.
What it does is allows you to change what Facebook page persona you post as – so if I’m on my band’s page and posting as “My Band’s Name” for comments, likes, etc., I can click the Change to… option (as seen above) and post, comment and like as myself.
…and if I want to change back, I just click the option again. How sweet is that?