I avoided riding with headphones for a long time. I simply wasn’t that comfortable with my ears covered – especially in busy San Francisco traffic. I had experimented a couple of times with riding with one earbud in. But this invariably lead to me either hearing only half of the music, or switching back and forth between stereo and mono settings on my iPhone. Neither of these options were particularly appealing.
However, after a little shopping on Amazon I came across the Far End Gear XDU stereo earbud. It plays both the left and right stereo channels it a single earbud.