There are two main types of GPS receivers available in the market at the moment:
Plain GPS receivers
GPS receivers with maps
A plain GPS receiver simply interprets the readings from the satellite and returns the result in latitude, longitude, and altitude. Figure 9-5 shows the PocketMap (http://www.pocketmap.com) PMG-220 CF GPS receiver. You can use the PMG-220 on your Pocket PC or your Windows XP notebook (which requires a PCMCIA sleeve for the CF card). Plain GPS receivers are useful in cases where you want to use the receiver interchangeably on your Pocket PC or Windows XP notebook computer. You also have the flexibility to use them with any other mapping software.
Figure 9-6 shows the Emtac Bluetooth GPS receiver. The nice feature of this receiver is that it does not occupy a Compact Flash slot on your Pocket PC for GPS functionality. You can connect to it wirelessly using Bluetooth and position it at a location where you can get a good signal.
Figure 9-5. The PocketMap PMG-220 Compact Flash GPS receiver with a CompactFlash to PCMCIA sleeve
Figure 9-6. The Emtac Bluetooth GPS receiver
Figure 9-7 shows two standalone GPS receivers equipped with their own mapping software. The Magellan Meridian Gold and the Garmin StreetPilot III contain built-in screens to display maps. ...