The scholar John William Burgon is remembered for the last line of his prize poem Petra, describing that inaccessible city: "Rose-red city, half as old as time". It seems he otherwise had a busy and productive scholarly career, but no one is interested in that.
One line? At the moment, anyway, my internet fame comes from one line as well: "The road to truth is long, and lined the entire way with annoying bastards". It comes from my first book, Carve the Sky. How it escaped into the wild is unknown, but it certainly has proliferated, most recently in the form of sweatshirts and hoodies.
There are certainly other usable lines in my work. One a friend always uses is from my Future Boston story, "Focal Plane": "An efficient technology is like the flu: sooner or later you end up with it."
Or, boiled down from something Norbert Spillvagen says at the NEO Diner in Brain Thief: "Accept the cowgirl". Now that I'd like to see on a T-shirt.