Looks like your 260 will store a trip or tracking log (Tools->Settings->Map->Trip Log->Show). A trip log is all you need for geo-tagging photos. Most DSLR cameras won't read a tracking log and geo-tag, you can find a built in gps easier. I use a program called HoudahGeo, but iPhoto and Aperture will read your trip log and geo-tag your photos.
You can do it very simply in BaseCamp: Edit:Geotag Photos from track....
If I double click a track, I can match photos to track using the drop down gear menu. I have to browse and locate a folder with photos taken while the track was being recorded. You can easily save the geo data to the photos.
I would thing most mac users geotagging photos would be using iPhoto, Aperture, or Picasa to organize the photos. It not easy to find you photos in any of the application used to organize photos. Several geotagging apps will bring up the mac media browser which allows you to view your photos for selection but the latest version of iphoto, Aperture, Picasa, and many websites have geo tagging functions.
Using BaseCamp 3.2.2 mac, the match photo function does not write the elevation data into the photo. Meanwhile my iPhone does! C'mon Garmin!
Are you using maps that actually have DEM (elevation) data? BaseCamp only facilitates this function. If you don't provide the Maps then - no Elevation in your Geotag.
