No GPS on any of the touch. Modified bluetooth stack by "Roqy" works fairly well and he is still pushing updates. I have a 2G 32GB touch with the RoqyBT stack installed. It pairs with a Holux 240Slim and a Holux M1200-E, both work well. In a contest to show correct position with a friends 3GS iphone my setup wins every time because of the weak location aided GPS of the phone. I have TomTom and it works well, as does Memory-Map.
It is a shame that Apple hobbled a perfectly serviceable BT unit in their devices. Its all very well having access to maps via data plans and WiFi but not much use when you are out in the sticks where you might want to explore via a map or turn by turn directions.
I bought my ipod touch purely with the hope that i could get GPS working and use offline mapping. I am glad I took the chance as it works very well.
When budget concious boaters can find a quality enclosure they will be very interested in Apples ipad offering paired with a good GPS dongle. 1500 cheaper in any good currency than a Pana Toughbook.