Ever since the car radio was invented, music has been a popular way to pass the time on a road trip. Before the 8-track tape was invented, all you had to listen to were the radio stations within range of your vehicle. Now, thanks to recent technology, you can listen to just about anything, just about anywhere.
There are several ways to listen to music in cars these days. Most vehicles still come equipped with CD players, but those seem to be dwindling in popularity thanks to mp3 players, which can store an entire library of music in a unit no bigger than a pack of cards. Satellite radio has also become more prevalent over the last few years. It differs from traditional radio in that you can listen to dozens of preset stations broadcast from a satellite, meaning they never fade out of range. This medium is also useful for travel because it offers weather and traffic reports for many cities across the country.
If you're looking for an alternative to music, audio books can be found in CD and mp3 format. Another popular form of audio entertainment is the podcast, a produced audio program often broadcast exclusively over the Internet. With all of these choices, you could drive around the world and never hear the same thing twice.