For personal use

GMap
For Garmin GPS recievers, laptops & PDAs w/ Garmin software installed(this little bugger saved my ass a couple of times-when MTS and BFT/FBCB2 failed this prevailed)

Maptech
For laptops & PDAs

Both are made by LeadDog Consulting

Google Earth
Download and toy around with up to date sattelite imagery-Impressive resolution. Subscribe to the Google Earth Plus and add GPS tracking capability