I found the iPhone app gps2ip and got it to send gps data to kismet on my laptop.
nc -l -p 11123 | tee /dev/ttys0
When I have time I'm going try to run it on the nano. A pineapple nano and an iPhone4 would make a nice small wardriving/walking rig.
If if there is any interest I can post my notes on the set up.