If you already have a handheld gps you can use it. This weekend I started experimenting with using my old Garmin eTrex Legend. I upload the track with easygps (free program that I also use for geocaching) and sync the track with the folder the pictures are in using GPicSync (free program that I just downloaded last week just to try). I went for a bike ride this weekend and took my camera and my Garmin. Once synced together all my pictures were geotagged. It's a few extra steps but since I already had my old Garmin it didn't cost me a thing. I also plan on trying this with my Garmin Forerunner that I use for biking and running. It's a watch so it might be a little more convenient than a handheld GPS.