From Pholix Software:
Easy-to-use, fast and comprehensive image browsing and viewing software for Win. PhotoPhilia provides you with quick viewing of 30+ image formats, simple explorer-style user interface, and true parallel processing for all time-consuming operations. Mosaic generates thumbnails with various sizes and appearance. You can organize your images into Albums, search your images by file name, date, size, keywords, categories, comment and by the Looks Like criteria. PhotoPhilia uses image cache and read-ahead technology for better performance. The program can convert images into various formats with many options, print your images, mosaics and whole albums easily. TWAIN support provides you with the ability to get images from scanners and digital cameras directly to your albums. File management, clipboard and drag-and-drop support, slide shows with 186 effects, applying brightness, contrast, saturation and hue to the image without modifying the original file, Install/Uninstall procedure and many other features.
there are plenty of photo organizers that can do albums and slideshows, but this is the only program i found that is able to display multiple images on screen, each in its own window. very good for quickly comparing images.