Earphones / Headphones: Where to try, what to buy?

God knows how many times an iPod (music, to be politically correct) listener has walked right out in front of me. I can't help but think the same goes for cyclists...

each to their own in any case.

i think it's unsafe to listen to music while riding, so i don't do it.

Everyone else, do what you want, i know whats good for me, and I'm sure you know whats good for you.

Once again, I respect that you're not trying to change anyone's mind, but what makes it okay for drivers to listen to their ipods while cyclists and peds are seen as unsafe when they do it?