Faviconer - Faviconer.com, or favicon generator, is online tool for creating favicon.
noesis - Rich Whitehouse's project web site.
ConvertIcon! - Converticon is a simple icon utility.
GraphicConverter - Graphic Converter for Mac and Windows, can converts image formats BMP, JPG, GIF, ICO, PNG, TIF...
Ordinatore - Those who want to tidy up their Macs will surely love this application.
FastStone Photo Resizer - Convert and Rename images in batch mode Support JPEG, BMP, GIF, PNG, TIFF and JPEG2000