Audible.com is offering you a free audiobook right now, if you do one of their free trials.
The free trial lasts for 2 weeks, and you will get credit for 1 free audiobook.
If you let the trial run past the 2 weeks, they will start to charge you ($14.95 per month, for 1 audiobook). But if you cancel before the end of the 2 weeks, you won't be charged a single cent.
Have you ever listened to a book? The first book I ever listened to was Guards, Guards, a Terry Pratchett novel. I really enjoyed it - it was very relaxing just to be able to listen to a story. I think audiobooks are a great idea to keep you entertained while you're out for a walk, or even exercising at the gym. It could be just the incentive I need to keep on exercising.
P.S. I'll paste the full T&Cs in here just for future reference:
Get your first 14 days of the AudibleListener Gold membership plan free, which includes one audiobook credit. After your 14 day trial, your membership will renew each month for just $14.95 per month so you can continue to receive one audiobook credit per month plus members-only discounts on all audio purchases. A very small number of titles are more than one credit. Cancel your membership before your free trial period is up and you will not be charged. Thereafter, cancel anytime, effective the next billing cycle. Any unused audiobook credits will be lost at cancellation.