That's relatively easy to write. I have been using such a script for 2 months in order to map WiFi points while walking. Very convenient.
The same script is used to map GSM BTS.
db
Have you published this script yet? I would be very much interested in seeing it.
By the way thoughtfix do you think that the 770 would work well for geocaching?
I'm not thoughfix, but I will answer to your question anyway:-) I started searching for cashes a few weeks ago, with my n800 and maemo-mapper. I made an application to load a list of cashes in maemo-mapper's POI db and the rest is easy. Just try to find some with maemo-mapper, you'll see that you don't need anything else. http://ioanghip.googlepages.com/wingeo.htm