IcoFX - IcoFX is an all-in-one solution for icon creation, extraction and editing.
Icon Editor by RedKetchup - View and edit Windows icons (ICO files) directly from the browser. Create icons in 8-bit, 24-bit, or 32-bit color depth. Extract all the layers of an ICO file as PNG images.
png2ico.com - Fully featured free online PNG, JPG, TIF, BMP & GIF etc. to ICO converter from sohOpen.
IconWorkshop - Application to create and manage software icons. A must for developers.
Online Favicon Generator & Gallery - Online favicon generator & creator provides to convert image GIF, JPEG, PNG and download in favicon.ico format 16x16 or 32x32 pixels or HTML code. This website also has a fantastic favicon gallery with download.
IconLover - Icon editor for Windows.