Currently a working prototype, the Apple Peel 520 is a case which contains all the electronics necessary for communicating with a GSM network.
The electronics include a SIM card slot, Infineon baseband chip and a battery, all of which will connect to the iPod with the dock port. The whole setup will involve jailbroken apps to be installed to make and receive phone calls and messages.
This thing is far from commercial production as of now, however, if it were ever to emerge in the market, it will probably cost around $44 – $74.
