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

Oh, also, does anyone know where the flagship Virgin store is? The bigger the store, the more choice there is!

Have you been lurking in a cave for the past year or so?! Virgin was rebranded zavvi about a year ago, and has subsequently gone bust.

Also, If the headphones are noise cancelling, irrespective of the volume you have them set at, surely they will still cancel noise? therefore rendering you unable to hear traffic?

And yeah I know, different strokes for different folks. I don't feel safe doing it, others do and they don't crash so it must be possible