Faviconer - Faviconer.com, or favicon generator, is online tool for creating favicon.
IcoFX - IcoFX is an all-in-one solution for icon creation, extraction and editing.
ConvertIcon! - Converticon is a simple icon utility.
IconWorkshop - Application to create and manage software icons. A must for developers.
Ordinatore - Those who want to tidy up their Macs will surely love this application.
IconLover - Icon editor for Windows.