editing exif data

I'm liking the geosetter tool (http://www.geosetter.de/) for updating the date and other metadata "EXIF" information on jpegs. With all these scans of photos it is invaluable to be able to put the correct date on pictures. Geosetter also allow me to put comments, aka "captions," in the jpeg file that is displayed be Windows and Picasa as a caption. The tool helps me put in latitude and longitude and a ton of other metadata.