tangoGPS is an easy-to-use, fast and lightweight mapping application for
use with or without GPS.  It runs on any *nix platform from the desktop
over eeePC down to phones like the Openmoko Neo.  By default tangoGPS
uses map data from the Openstreetmap project. Additionally a variety of
other repositories can be easily added.  The maps are automatically
downloaded and cached for offline use while you drag or zoom the map.
Furthermore you can conveniently pre-cache areas with tangoGPS.
To get real-time positioning from a GPS receiver you need to run gpsd.