kml seems to be more applicable ... for output ... don't have much experience but there are many tools/apps for it - when i remember correctly it can be parsed and displayed with osm-libs, also Openrouteservice gives u a kml-file (damn, time is running, its over one year since we discussed and experimented with osm a bit)

i think i'm quite interested in helping development if needed/wanted, but have to say its my first python approach also.

i'm thinking of a push/pull-app, so u have a frequently updates and the ability to request current coordinates. maybe it not only should relay on data-connection but also could send/receive cmds via sms/call.