Finally got myself a Nike Mobile Case (flash!) , which wraps around your arm. This shortens the length between cord and earphones.

The Centro actually is a good music player. With Pocket Tunes upgrade (which I had from my TX), it plays all my media files including Ogg Vorbis. Only annoying part is that you need a bulky 3.5in adapter.

I put my Centro upside down in the case so that the headphone jack is at the top. The case stretches nicely to cover the adapter and also excess cord. Once adjusted, the cord length is very short, so there is almost no flapping due to movement. Matched with my MX55's this allows me to run and do stuff while listening to music. I'm going to have a go next weekend to see how well this setup holds up to a morning jog and shooting hoops which was the main reason to look for the headphones and case.