It's become an idiom. Stoplights may not be the best way to control intersections, but you know what to do when you see one.

The first time I remember seeing it was on Chrome. Who was the first to use it? I personally don't think it has much value, in and of itself, as a graphic.

What would you replace it with? I struggle with how to offer nav menus on narrow screens... I'm not in love with the hamburger icon, but it seems to have become somewhat of a standard (which I think is more important for UI elements than pure aesthetics). I'm always on the lookout for alternate solutions to try!

I'm ashamed to admit that it took me a while to figure out what the "hamburger button" is. Never heard it called that before. :-)