Para quem tem um PDA ou smartphone, com Windows mobile, aqui fica um software GPS que encontrei e me parece muito porreiro em termos de funcionalidades para utilização off-road.
Este software num PDA, com um suporte e caixa Ram-Mount permitem obter uma substituição low-cost de um equipamento GPS específico.

Pathaway
Este programa pode ser adquirido no site indicado no final do post ou "encontrado" na internet

Quanto aos mapas a usar, o programa pode funcionar com download gratuito de mapas do Google Maps e outras fontes, bem como com diversos formatos de mapa que podem ser convertidos para funcionar neste programa.

Características:
GPS Navigation
Use the internal GPS of your device or attach a compatible GPS (Global Positioning System) device to your Windows Mobile - Pocket PC, and use PathAway to navigate. PathAway works with all of the leading GPS handheld devices. PathAway supports all Windows Mobile devices with internal GPS receivers, as well as extrenal Bluetooth, cabled, sled-based, and SDIO GPS devices.

Maps from Anywhere
Import your own maps using the free Map Manager, or third-party Desktop Mapping Software such as Touratech-QV, Fugawi, or SoftMap. Get maps from mapping web sites, CD-ROM, scanned, or digitally photographed. Maps are highly compressed and can be any size and resolution that fits within your device memory.

WebMaps - Download Internet maps on-the-fly
Web Maps allows you to download maps on-the-fly from a Map Server on the internet. Maps will be downloaded in the background and displayed on the screen as they complete downloading. Maps are cached, so downloading only needs to be done once. Maps currently supported:
Google Maps: Worldwide street, satellite, and terrain maps.
Terraserver-USA Maps: USGA Topographic and aeriel photo maps. Covers USA only.
OpenStreetMap.com: User contributed Street Map Community. Covers most of World.
OpenCycleMap.com: User contributed topgraphic and terrain maps. Covers most of World
X-Traverse: Map sets provided by http://X-Traverse.com. Mainly topographical and marine charts.

Intelligent Moving Map Display
As you travel, PathAway will center the map on your position. When you exit the boundary of one map and enter another, PathAway can be setup to automatically switch to the new map. You can even have the software set to automatically zoom in to the map of highest detail when you reach it's boundaries. Great for when you're entering a destination point that requires precision detail.

Track Up Navigation:
Automatic or manual Map rotation for travel direction up display.

Map Projections and Datums
PathAway supports the most popular Map Projections and Datums, for precision location pinpointing.

Coordinate Grids:
Display positions in coordinats such as Latitude/Longitude, UTM, OSGB, Quebec-MTM, MGA, MGRS, GGRS87, Swedish Grid, Irish grid, or Israel Grid and more.

Personal Points of Interest/Waypoints
Capture unlimited points and record detailed names and descriptions. Attach your own custom icon, picture or sound clip for easy visual scanning.

Record and Follow your Tracks
Record your track as you travel. Then, follow the recorded track to find your way home.

Point to Point Routing
Create routes quickly by simply clicking points on a map, or by choosing from your point database.

Navigation Warnings and Alarms
Proximity detection alerts you to upcoming points along your route, or when you get close to one of your points. If you're following a route, PathAway will alert you if you've strayed off-track, or if your elevation has strayed beyond the level stored in the route. You can even add your own sound clips to be used for any of the available alarms.

GPS Sky View and Satellite Data View
Analyse GPS Connection to determine quality of reception.

Compass View
Customizable Large Compass view screens showing Heading, DIrection to Next Point, next turn, or any other available navigation data. View multiple Compasses on the screen at the same time, or a single large compass.

PocketMode Power Save Feature
You can now track via your GPS, and save battery life at the same time. Once you enter PocketMode, PathAway turns off the screen (or backlight depending on device), and locks the keys but continues to record GPS data to your track log. If you using a Bluetooth GPS, simply connect the GPS, enter Pocket Mode, and put the handheld in your Pocket! No need to worry about accidentally hitting keys to issue unwanted commands. Use the special key sequence (or power button) to exit Pocket mode and return to the View screen.

Manual And Proximity based Route Point Targeting. Manual means user must select "Advance Route Point" before PathAway will target the next point in sequence. Proximity means you must enter within a proximity of a route point before the next point will be automatically targeted.

Measure Area or the distance between points
Want to know the distance between 2 points on the map? With the Measure tool you can just click 2 points to get the distance and direction. You can also determine the area of one of your routes, or recorded track logs.

Large size Icon and Text Menu display
Double the size of the icons for better viewing, or enlarge the text on the menus for arms-length viewing, or easier finger selection.

Import GPS data from Data Logger NMEA file
Download data logged in your Data Logger GPS, (I.e.. RoyalTek BlueGPS.) and import the NMEA file directly into PathAway.

Import Data Formats
Google Earth KML, GPX, LOC, and other formats supported via PathAway PC Conversion Tools, or directly on your handheld. Great for GeoCache users.

GPS fix acquired and lost alarms
Receive audible alerts when a GPS fix is acquired or lost.

Onscreen Trip Statistics on a Customizable Dashboard
Display the information you need while still having a great view of the map. Custom 12 edges of the screen to pop-out to show the info. Stats such as ground speed, average and max speed, and vertical climbe/descent speed. elevation, geographic coordinates, directional heading/ ground distance/vertical distance/vertical angle to next point, turn or destination. Odometer, elapsed time, Estimated time enroute,

Pocket PC 2003, Windows Mobile 5 and 6 Support - Pocket PC and Smartphone
PathAway Standard Edition runs on the latest Windows Mobile Handhelds. Current versions run on Pocket PC 2002, 2003, Windows Mobile 5 - Pocket PC, Windows Mobile 6 - Professional/Classic and Standard operating systems.
PathAway Professional Edition runs on Pocket PC 2003, Windows Mobile 5 - Pocket PC, Windows Mobile 5 Smartphone, Windows Mobile 6 - Professional, Classic, and Standard.
PathAway is also confirmed to be compatible with Windows Phone (Windows Mobile 6.5)

Transfer Data To and From Garmin and Magellan GPS Devices
PathAway works great as a waypoint, track, and route manager for your Garmin or Magellan handheld GPS. Backup all your data on the GPS in PathAway. Create Routes using PathAway and your own maps, then upload the route to the GPS.

Get your maps from mapping web sites, CD-ROM, scanned, or digitally photographed. Use the free PathAway Tools for Windows to prepare and manage maps. Maps can be any size and resolution. Maps will be converted to an optimized PathAway format for efficient handling on your handheld.

Get Maps from 3rd party applications.
You're not limited by using the PathAway tools. You can also use powerful desktop mapping software that supports PathAway format. See our Links page for more info.

Mais informação em: http://pathaway.com/PWWinMobile.htm

Outro software, este muito mais fácil de usar mas também com menos funcionalidades.
Tem como grandes vantagens ser freeware, permitir o download directo e gratuito de mapas de vários sites (ex: GoogleMaps) e a sua utilização ser muito simples.
Mais informação e download da aplicação no site abaixo:
http://navicomputer.com/

Funcionalidades:
Offline map navigation without internet connection/dataplan
Easy map download from online mapsources like OpenStreetMap
Finger friendly and fluid user interface
Track recording with stats like distance, av.speed and elevation profile
Conform to the common gpx file format (import and export)
Multilingual user interface (English, German, Spanish, French, Italian, Dutch)

Atenção ao Compegps ou Twonav, muito bom!
Permite meter ortofotos, o que dá muito jeito quando se anda perdido e os Mapas de GPS nao têm os caminhos todos. Para além disso e de todas as funcionalidades que os outros também têm, a versão desktop é excelente para importar e exportar tracks de e para o Garmin, editá-las, vê-las sobre as imagens aéreas, etc.
Recomendo vivamente, até porque não é caro

Com estas é que eu vejo que estou a ficar velho , não percebi um boi

És tu e eu...nem estive a ler....fonix!
Aqui fala-se PORTUGUÊS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Já agora , o que é um ortofoto ?

São fotos aéreas, tipo Google Earth

São fotos tiradas por "ortorrinos"

O site do williamcacos http://williamcacos.blogspot.com/ diz há uns tempos que vai ter ortofotos de Portugal inteiro... Mas acho que vai demorar mais um bocadinho...

Do Norte já tem há muito tempo.
Já me deram jeito mais que uma vez.

Boas

Para quem quiser mapas do google earth pode usar este link ke faz mapa como quiser para meter no ozi ou compegps
http://www.mapcacher.com/

Outro software GPS para PDA é o Garmin Mobile XT, que permite a utilização de mapas Garmin.

Não sei ao certo que tal é para navegação off-road pois ainda não o testei; estou com dificuldade em arranjar um mapa topo de portugal.

eu uso o Ozi, no meu caso o Ozi CE, com cartas militares, ou com mapas ou fotos criados do Openstreetmaps ou GE, entre outros.

Num NDrive com sistema Windows CE, e tem funcionado muito bem.

o problema que tenho é converter os ficheiros GPX (que a malta normalmente usa) para formato que o ozi leia,

Já que se fala sobre GPS e afins, pergunto se alguem tem dicas para actualização de um MOTORRAD III, pois o meu já conta com uns anitos e já falta muita palh.....caminhos e estradas

Eu era muito feliz com o meu zumo 500. Agora que sei que existem ortofotos, Compegps e Twonav, já nada será igual

O meu Ndrive conseguimete-lo a funcionar com o oziexplorer e ortofotos, muito bom, estou é limitado pela pouca memória do GPS, o coitadinho arrasta-se,