I have used the same headphones for years – the Plantronics Back Beat Fit headphones (I may be on my second pair, though I think they have actually held up for a very long time). I love them. They are water proof (and trust me, we get some rain here in Juneau, Alaska). They don’t work too well for talking on the phone, though they can work. They are wireless. They fold up and can be thrown in a bag. They are everything I could ever want in a headphone for sport. (Hopefully it will stay that way, as I wrote earlier, when we find something new sometimes we do not turn back).
Also, I wrote recently about the Ironman company, here is an interesting article about a company seeking to compete with them.