Here are brief specifications of the iMac and GPS receivers.

iMac Aluminum 24"
2.8 GHz Intel Core 2 Duo
4 GB SDRAM
465GB HD
OSX 10.4.10

Vista HCx
2GB micro card

GPSMap 60 CSx
2GB micro card

Maps and associated software.

iMac

National Geographic TOPO software
NG Colorado 24,000:1 topo map
Scanned USGS topo maps, no enhancement

MacGPS Pro software
MacGPS Pro CO 24,000:1 topo map
Scanned USGS topo maps, no enhancement

Vista HCx and 60 CSx

Above the Timber
Colorado 24,000:1 topo map (vector format)
installed on each micro card
Based on USGS DRG maps and enhanced with POIs and other information.

Software for transferring data.

iMac

TOPO and MacGPS Pro transfer data:
<-- waypoints and tracklogs
waypoints, tracks, and routes -->

Mac OSX is used to copy files:
<-- GPSX files
Above the Timber map -->

GPS receivers

I use Google Earth (Max OSX version) to view some of my data and to build waypoint and route files (manually) that I upload to my GPS receivers.

I use GPS Babel to convert gpx files into KML files for input to Google Earth and for converting KML files from Google Earth back into gpx files for TOPO and MacGPS Pro.

GPS rcvr --> gpx file --> GPSBabel --> KMZ file --> Google Earth

TOPO <-- gpx file <-- GPSBabel <-- KMZ file <-- Google Earth

MacGPS Pro <-- gpx file <-- GPSBabel <-- KMZ file <-- Google Earth

I use GPSPhotoLinker to georeference pictures and then input the pictures to Google Earth where they are shown as a camera icon in their assigned locations. If the data provided to GPSPhotoLinker is accurate, the pictures will be accurately placed on the Google Earth photos. When I click on a camera icon, a picture (and optional text) pops up.