I recently have been taking on a great free treat, podcasts. I am a mac user, but those of you with windows can also use iTunes to get a vast directory with every topic under the sun in podcast topics. Take an astronomy class from UC-Berkley, learn daily Spanish, or subscribe to podcasts on learning how to be more "green". If you are into talk radio, this is another great outlet as well, since topics can be specific to your own interests. Also, I know in the case of my husband, he has a particularily long commute to work every day, so there is always room to take advantage during the daily drive to play podcasts on American civil war history (yuck!). There are also video podcasts available too, if you like to watch your speaker. I like to load up on a podcast before a long trip on an airplane or by car on our journey back home, it makes things much more enjoyable and time go a little faster.
You don't need an actual iPod to use "podcasts" either, any mp3 player can work just fine! Depending on the length of the podcast, you may also be able to burn them on to CDs, if you do not have a type of mp3 player transmitter to your car radio. Grow your interests with podcasts, its knowledge at your disposable, with entertainment on the side. The list of podcasts on iTunes is growing every week too, so check back every once in a while!