Optimage - Advanced image optimization tool
ImBatch - ImBatch is a batch image processor with a nice graphical user interface.
ImageOptim API - Web service for image compression
DVDVideoSoft Image Convert and Resize - Free Image Convert and Resize is a compact yet powerful program for batch mode image processing.
Imagify - Optimize and resize images online and through your CMS.
Fotosizer - Fotosizer is a freeware batch image resizer tool. It resizes your photos in just 3 easy steps - 1.