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.
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.
FILEminimizer Pictures - FILEminimizer Pictures compresses JPEG photos, TIFF, BMP and PNG images and pictures by up to 98%.
Ralpha Image Resizer - High-speed image batch conversion tool