QT1  GPSPhotoLinker can do a bit of this, and you can add the GPS data to your photos before import to iPhoto http://www.hutsby.net/search/label/GPS  
(Version 1.4.3)

KWTGM  I had a look at all the geo-tagging software I could find for Leopard. Geotagalog is by far the best for my needs. I have an AMOD GPS logger, which creates NMEA files. I just drag those onto the Geotagalog icon in my dock, select the folder with the images and let Geotagalog import the geo-tagged images into iPhoto 9. Perfect for my needs.

Now I just which I could use Geotagalog to export the tracks to Google Earth. But for that I use the free JetPhoto Studio that shipped with the AMOD.  
(Version 1.4)

FLYING ACE  Excellent App! My GPS tracker arrived in the mail today, and I went out for a quick drive to see how it all worked. When I got back home, I fired up the software that came with the tracker and was confronted with a bewildering array of options. Sat down with the software for an hour trying to work it out, and I just got sick of it. I jumped on MU and came across this little gem.

Load the log file, import the images, and it's all placed into iPhoto within seconds! Couldn't be easier, and it will make my upcoming 9 week trip to Europe a much more enjoyable experience!  
(Version 1.3)