There a couple of things that can totally ruin a good run: shoes that hurt; a bad playlist and chafing from an arm band carrying an iPhone, iPod, etc.
Let me tell you how excited I was when I came across this option when carrying your playlist. I have tried holding my iPod ( did not llike at all!) - and I have one of the velcro arm bands. However, this can leave a painful burn. What did I find? The Flipbelt.