When I use a mouse, I use All in one gesture (Firefox add-on) and mapped "go back" and "go forward" to mouse right button and move mouse up and down. (my mouse doesn't have back and front buttons). It really works well.
I have the latest synaptics driver and it has this three finger thing - place three fingers on the touchpad and move left to go back or move right to go forward in a browser. But I find that it puts strain on my wrist. All in one gesture add-on doesn't work for well since it is kind of hard to press the touchpad buttons. Right now, I'm using the "Alt key + left arrow / right arrow" to go back and forward most of the time.
What do you use for "go back" and "go front" other than actually hitting the green arrow buttons in the browser?