Looks like Audible has swung a deal with The Teaching Company, and is offering at least some of their "Great Courses" series as Audible purchases. They're doing a back-to-school themed 3-for-2 sale, and that's pretty good value when compared to the prices the Teaching Company series usually go for. $10-15 is a really nice price point for their stuff, most of which are very good.
http://www.audible.com/sp/3for2/ref=..._1_tab?tb=tab1
I can personally vouch for:
The World Was Never the Same: Events That Changed History
Economics, 3rd Edition
The Will to Power: The Philosophy of Friedrich Nietzsche
Mysteries of Modern Physics: Time