exiftool is very cool

I discovered this command line tool called exiftool written by Phil Harvey. It is a platform independant Perl library used to manipulate, edit, read, write exif data in photographic images. So far I've written a bash script to geotag images using user supplied geographic coordinates (DMS format) but it can also use GPS log files to geotag and geosync your photos. By default it creates a backup of the original but can also write over the original instead. It looks like a pretty powerful little tool. I think it was about 8MB to install it and it is freeware.
http://www.sno.phy.queensu.ca/~phil/exiftool/