Geotag your photos easily from the shell
http://namakajiri.net/code/geotag-exif
This is a simple wrapper over exiftool (debian/ubuntu: in package libimage-exiftool-perl) to make it easy to set EXIF geographic information (GPS tags). It is able to understand the decimal format for latitude/longitude that you can get from google maps, wikimapia etc.
With exiftool:
exiftool \
-GPSLatitudeRef=South \
-GPSLatitude=23.88 \
-GPSLongitudeRef=West \
-GPSLongitude=49.81 \
pic.jpeg
With geotag-exif:
geotag-exif pic.jpeg -23.88 -49.81
It won’t touch your EXIF tags other than the GPS tags and the FileLastModified timestamp.