Your GPSr when plugged in to a computer will/can be just another portable hard drive, like a memory stick.
Personally I'm now running a Garmin GPSMAP 62s and use a Mac to load the .gpx files on to it.
Dead simple, I just drag and drop the files on to the GPSr as I would on to a memory stick.
The Garmin then get all the info about the caches, positions, descriptions, hints and even previous logs.
Whichever way you go, enjoy yourself!