Bonus points for doing this while going down. Taking public transportation as part of my daily commute involves a lot of stair climbing and descending. I always find it fascinating to watch the people who rush from bus to train platform and watch them descend 2 stairs at a time (basically always doing long long long) the whole way down. I've never been brave enough to try this method of descending though.
For some reason I always (if reasonable, and that's often) climb and descend two steps at a time, like you describe. It's quick, and doesn't even tire much more than doing short-short-short, since while the exertion is a little higher, the entire staircase takes a lot less time. At some point you get good enough at this stuff to descend a staircase, quickly, at a busy train station (somewhat; can't be too busy becaus…
Really kind of scared a friend once doing it down stairs... he was pretty concerned for my safety!