Shrink O'Matic - Shrink O'Matic is an AIR application to easily (batch) resize (shrink) images.
Caesium Image Compressor - Compress your pictures up to 90% without visible quality loss.
XnConvert - XnConvert is an easy image converter for graphic files, photos and images available on Windows...
ImageOptim - Faster web pages and apps.
DVDVideoSoft Image Convert and Resize - Free Image Convert and Resize is a compact yet powerful program for batch mode image processing.
ImBatch - ImBatch is a batch image processor with a nice graphical user interface.