The most popular jailbroken application on the ipod touch or iphone. It was created by Jay Freeman, otherwise known as Saurik. With this, people can download jailbroken programs such as system themes, system fonts, emulators, wallpapers, etc... basicaly anything that can change how your ipod does things. You can also use a paypal account to download some programs that require a purchase. Most programs available to download though, are free. There are roughly around 45,000 daily users. More programs are added everyday. It has replaced the once popular jailbroken app, installer.
I just got my ipod theme from Cydia.