This is what you want....
http://www.amazon.co.uk/Apple-MA070G.../dp/B000MTEER4
Here is the iPods it works with....
iPod nano (1G), iPod with video (5G), iPod nano (aluminum) (2G), iPod classic, iPod nano (aluminum) (3G)
I bought one when it first came out, think it was 4 years ago, works well, when you plug it in it adds a new menu to your screen, its only a FM tuner by the way, you wont get AM or Digital.