Install Maps to Garmin Devices using MapSource | Garmin Customer Support
GPSMap 276CX : Aerostich RiderWearhouse
Garmin 010-00322-00 Handheld/Portable System, GPS 60 with Worldwide City, POI Database, Sunlight-readable, four-level grayscale transflective FSTN display, 1 MB of internal memory for storing MapSource POI data, 50 reversible routes, 10,000 track poi
A portable Mapsource or BaseCamp in your pendrive ?
Garmin GPS V Hand HeldGPS
Amazon.com: Garmin StreetPilot III 6.8-Inch Portable GPS Navigator : Electronics