¡Mierda!
After upgrading the firmware, my N900 doesn’t auto-tag photos with the current GPS coordinates anymore; may be a Layer8 problem, haven’t had time yet to investigate.
To circumvent this, I enabled the history on Google Latitude, the big G now keeps the logs for me to see — and to export into .kml. I don’t know much about KML besides that’s another chatty way to store data instead of good old, sed-able, CSV … For batch-geotagging files I use gpscorrelate(-gui), which needs .gpx — fortunately, gpsbabel promses to convert e. g. .kml into .gpx. And it does, but regardless of the options (none, -t, -r), it leaves out the timestamp a waypoint was taken at; and without timestamps, gpscorrelate can’t correlate coordinates to pictures, thus it just gives an error trying to read the .klm converted to .gpx.
So, before making a 5-minute-issue a whole-day-coding event: anyone knows either another Linux application that can (batch-) tag photos with GPS coordinates from a (Google Latitude-) KML file or a way to convert the (Google Latitude-) KML to gpscorrelate-usable GPX format?