...using it with the Wayfinder GPS Software on the SE P800

You're using the Wayfinder software ? How do you like it ? Is it any good ?
I've considered this software too for my Nokia 7650. Does it need GRPS or is WAP just fine? And when it uses GPRS, does it need a lot of data transfer ? (over here, GPRS services have to be paid per used block of 100KB)

Sorry for hijacking the thread...

Back on topic then. I've also got a USB GPS device, and I've recently bought the Alturion GPS bundle. But I haven't had a chance to try it yet. It's this one. (bottom of the page)
I haven't tried it yet because realised that using a laptop while driving is far from ideal, and now I'm saving up to buy myself an IPAQ.