do you ever worry about having such excellent earphones when you're riding your bike, in that it's not safe to have the environmental sound blocked out?
I use different ear/headphones depending what I'm doing but with the better earphones, you don't need the sound up very loud because it's more clear and crisp.
For riding a bike or running I use the Sennheiser ones that are on the left. They sit in the ear and sound very good but don't block out the surrounding sound too much.
For walking around and on the bus, I use the Kliptsch ear canal phones on the right. Great sound and blocks out pretty much everything. iPod controls and a very good microphone. I use Siri on my iPhone quite a bit to make calls, texts and to change what I'm listening to.
I use some Denon over the ear cans in the house if I'm trying not to disturb someone else there.