ImBatch - ImBatch is a batch image processor with a nice graphical user interface.
ConvertIcon! - Converticon is a simple icon utility.
DVDVideoSoft Image Convert and Resize - Free Image Convert and Resize is a compact yet powerful program for batch mode image processing.
ConvertICO.org - Create icons from png, jpg or bmp images easily.
Batch Image Resizer - Resize, crop, shrink, flip, exif-rotate, convert, enhance, process multiple pictures and photos with professional software! 120+ Actions, 30+ Image Formats
Ordinatore - Those who want to tidy up their Macs will surely love this application.