Agree with Troute. I can also pair GPS dongle via Bluetooth but it actually doesn't do anything. So we need some developers to look into it. I'm not sure if Ndrive HD is available (at least it's not showing in UK app catalog) but maybe with Ndrive GPS dongles could be put into practice.
Patch Navit to include the option to use a Bluetooth GPS dongle by grabbing NMEA output over Bluetooth SPP as shown in the code example I linked, which shows JUST THAT. I imagine it would be near to a copy and paste job to get it working.
I got my Bluetooth gps today, but it doesn't seem to wanna connect to my pad.
It works for the computer (connects), but I havn't tested if it works with any program.
Well I did some searching and had success. There is a WebOS program that will work with external GPS. It's called MapTool Pro. It is not optimized for the touchpad yet and is a paid app.