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. A security confirmation dialog will appear in later versions of Java.
PhotoGrok dynamically displays photos and other files by metadata (and a whole lot more). It's powered by Phil Harvey's ExifTool. Java 6 or higher is required. Please read the FAQ.
See the scripting page for details on new scripting features including example code for image filters and a histogram.
Main Screen with Image Preview
Thumbnail Screen with User Tab (Including Custom Tags)
Bar Chart of Images by Camera Model
Exif Tab with ExifTool Composite and PhotoGrok Custom Tags