I occasionally listen to my iPod when cycling (to keep this on topic!), although I haven't since getting Ruby Roubaix.
But still and all, I don't like the stock ear buds that came with the unit. They want to fall out of my ear too often. I have discovered there are a wide variety of aftermarket alternatives, but I'd rather not buy one and find out it's not very good.
So...anyone with a recommendation?