Ralpha Image Resizer - High-speed image batch conversion tool
Faviconer - Faviconer.com, or favicon generator, is online tool for creating favicon.
ImBatch - ImBatch is a batch image processor with a nice graphical user interface.
ConvertIcon! - Converticon is a simple icon utility.
Caesium Image Compressor - Compress your pictures up to 90% without visible quality loss.
Ordinatore - Those who want to tidy up their Macs will surely love this application.