This website has one of the unique implementations (in a good way) of hijacking the browser's "Back" button.
As you scroll, and each story comes into focus, the URL changes to identify that story. This is good if the reader wants to share a story she is currently reading, and needs to copy the URL.
But when you press the "Back" button, instead of just changing the URL to that of previous story's, and scroll to the previous story, it takes you through your whole history on the website, all the way back to where you came from; back to HN, in my case.
Interesting, to say the least.
I'd love for it to _not_ bother cycling/scrolling through previous stories, as it's taking me back to where I came from.