Oracle has disabled self-signed web start applications in the latest versions of Java. To use this version, type "javaws -viewer" and open the "Security" tab. Add "http://www.haplessgenius.com" to the Exception Site List. You only need to do this once.
PhotoGrok categorizes photos and other files by metadata. It's powered by Phil Harvey's excellent ExifTool. Java 6 or higher is required. PhotoGrok now includes ExifTool for Windows, Mac and Linux users. Please read the FAQ.