One "new user" suggestion qnuite... on first run, you might want to ask the user where to store the map files.

The default is in device memory, but that's pretty small and if the user has an SD card installed they would probably prefer to keep it there (or in the 2GB memory in the N810).

I changed my file locations manually later, but that's a bit of administrative work I think most users would like to avoid... altering paths for 5 or 6 repositories and for the POI file and then cleaning up the old locations. A choice at the start would save users that hassle later.