Loglickychops,
Many GPS recievers will stream positioning data out the serial ports for use with a PC / PDA. Garmins for sure, and they do some of the cheapo models as well as the high-end handhelds. Windows 98 has drivers for a range of GPS units. Try adding new Hardware in Control panel, selecting the device from a list and choosing the type as Global Positioning Devices or whatever it's labelled as. Should show up compatible units.
Even then, there'll be drivers shipped / available for most GPS units that have a serial port.
Aq