Doesn't use the ipod bottom connector, so it uses the headphone jack. So you nano 3g won't work, because its jack is on the bottom. And there's no mention of the size, so you don't know if your larger ipod will fit, and assume your smaller nano 2g will just fall right out. You can find stuff like this at Walgreen's for under $10 and have a no hassle return if it doesn't work out.

FWIW I bought my kid something similar at Walgreens for $6 because my kid (IMO) is too young to be using earbuds. The headphone connector was on the bottom so the nano 3g just locked right in. But my 80g classic didn't fit well, and I didn't want to monkey with the headphone cord.