One reason for choosing OpenStreetMaps for APRSISCE/32 was that if your area doesn't have enough detail, you can add it yourself. It's an open-source data service. Just sign up with an account, grab your GPS, and add to the map.
Many of the Internet-based maps, in particular Google Maps, have usage restrictions that are incompatible with APRSISCE/32. Read them closely before using any particular map source.
That said, if you can find a map source (server, port, and URL construction), the instructions at http://aprsisce.wikidot.com/tile-sets describe how to configure APRSISCE/32 to use alternate OSM-compatible map tile sources.
Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and Win32
