If you are smart enough to save money with used iPods, you've probably also got a nice collection of iPod apps that were free or about a dollar. iPod apps have sold in the billions, and that's only counting ones from the Apple store, not the ones you can easily download with your jailbroken used iPod.

Compared to the early iPods, which came with a clock, calender, backlight, and some simple preloaded games, today's iPhones and iPads, which are replacing used iPods, can hold hundreds to thousands of games, still play most of your music, and can GPS you out of a bad situation (be it restaurant or neighborhood).

Still, used iPods can be a great way to collect more apps. Electronic devices are pervading everyday life to such an extreme that we're not just carrying around our own iDevice, but placing them where they might be useful… and iPad in the kitchen, and extra used iPod in the car, an iPod docked in the home stereo system, and an iPhone in your pocket. Adding free apps, or paid ones shared over your devices, can enhance each device… and based on sales, thats exactly how people are using them!

What are your top ten free apps for your used iPods?