IcoFX - IcoFX is an all-in-one solution for icon creation, extraction and editing.
Aseprite - Aseprite is an art program dedicated to the creation of pixel art.
Icon Slate - Icon Slate lets you easily compose, import and export desktop icons in many formats.
IconLover - Icon editor for Windows.
Icon Generator - Icon Generator is a little application built on AIR that lets you generate a CS5 or Web 2.
Piskel - Piskel is a website where designers online create sprites or pixel art.