Fm Connector On The Ipod Touch Or Certain Ipods You Can Buy A Connector So That It Transmits Through You FM Radio?

On the Ipod Touch or certain Ipods you can buy a connector so that it transmits through you FM radio? - fm connector

But even the new Nano does not have this possibility? I've heard that Nano is different.

Is that true? If so, why?

Thx!