[giles_bowkett]

I would get a Pimsleur CD course on a language you've always wanted to learn. The complete box set, 14 CDs or whatever, $250. You'll be conversational a few days later, and it requires you to listen actively rather than passively, so you're more likely to stay awake while you drive.

[olifante]

I have to second that recommendation. I've been studying Pimsleur's excellent Mandarin Chinese I, II and III in my daily commute and road trips for some time, and I highly recommend it. It requires reasonably active listening and sentence production, so it helps you avoid drowsiness on long trips.

Coincidentally, I'm leaving soon on a car trip to Morocco and was just preparing to sync the free Michigan Modern Standard Arabic and the Pimsleur Egyptian Arabic audio courses to my iPod.

[edw519]

I would strongly recommend the "Behind the Wheel" series of foreign language courses. There were specifically designed for use while driving. Perfect. N'est pas?

http://www.amazon.com/Behind-French-Revised-Complete-Illustr...