Listening to audio without obstructing ears I'm looking for a way to listen to my audiobooks while commuting without obstructing my ears.

One (rather expensive) option appears to be the Tunebug Shake (a Bluetooth turn-your-helmet-into-a-speaker gizmo); however, I'm hesitant to spend $120 on a device made by a company which does all their consumer promos with skater-style helmets and doesn't answer emails asking questions about sound quality with vented helmets.

Another option would be a water-bottle speaker (I commute with a Camelbak -- this is Austin, after all -- so either of these mounts are fine). Obvious downside is positioning -- my two water-bottle cages are below and behind my ears -- and several of the commercially available devices are specific to Apple hardware (and the thought of buying an iPod rather than using my existing Android-based phone smarts a little).

Suggestions? Experience?
I'm assuming you want those more to be able to hear traffic, less because how unobstructed ears look. I use a pair of cheap sony ear plugs. They're the kind of plugs that don't go all the way in the ear, but are only small round bulbs that sit at the front. Thus they still allow me to hear everything around me perfectly.