Audible.com

Visiting friends this weekend, I was introduced to Audible.com.  This morning I signed up for the three month trial period ($7.50/month for the first three months) and downloaded Hemingway's Steinbeck's The Grapes of Wrath.  I listened to almost two hours of it at the gym and on the way to work.  So far pretty impressed - the narration isn't dull or monotone and they even bring in another reader when there is an exchange and it might be unclear which character is speaking.

I would welcome any input from any Audible.com veterans.  Do "books on tape" work better for fiction than non-fiction?  As many of you know, I travel a good deal for work and am often not able to sit down with a book, but could certainly press play on my iPod.  This seems like a great way to take in 10-12 books a year during what otherwise would have been time spent staring at the wall.