Audible.com books on tape

[Entity]

For the most part, my iPod listening habits are mostly limited to CDs, concerts, and the like, with the exception of a few very good podcasts/regular radio programs (This American Life most notably amongst them). I have also downloaded a few programs on guided meditation to help me learn/focus on the process of meditation a bit, but beyond that, have never really delved into the books-on-tape market.

A few months ago (after I purchased a membership and some points), This American Life decided to start releasing their own independent free podcasts and not limiting all of their shows to paid subscriptions on Audible.com. This has left me with a surplus of points, and yet a strange reluctance to actually buying audiobooks on tape.

I've got a few books I've been thinking about buying (right now, Wikinomics is probably the highest on the list) and I'm wondering if anyone has gotten accustomed to the books on tape format for actual publications. I feel like I'd zone out a lot listening to someone, depending on what else I were doing, but really can't judge for sure -- so I'm looking for recommendations or warnings. Either way is great.

Rob