When you don't have a jailbroken ipod touch the only apps you can install onto it are ones created by Apple. After you jailbreak it you basically get an application called "Cydia." This app is exactly like the app store on your ipod. But instead of apps from apple, you get apps created by people all over the world! These apps allow you to change the sounds your ipod makes, change the way it looks, allows you to connect to it from your computer and add files to it manually, all sorts of stuff. And when I say you can change the way it looks, I mean everything, instead of sliding that little block to unlock it, you can make it looks like pacman! Or you can make it so you tap the bar instead. Or change the backround, the pics inside each little app, the volume bar, the volume icon, you really can change the way everything looks. It basically unleashes the full potential of your ipod, and in the end makes you want to pick up your ipod when you go somewhere a lot more
