The RedKetchup - Icon Converter allows you to convert an image into a compatible Windows icon online. It can also customize the icon background with a color or adjust its rounded corners. Finally, it can configure the image format and the color depth used internally by ICO files.
IcoFX - IcoFX is an all-in-one solution for icon creation, extraction and editing.
Online Image Converter - Online Image Converter converts your BMP, JPG, PNG, GIF or ICO files quickly and easily.
FavIcon from Pics - Brand your pages with a custom favicon.ico.
png2ico - Program to convert .PNG files to a Windows icon resource, such as used for website/bookmark icon favicon.ico. Available for different platforms.
JDraw - Open Source SF.net
png2ico.com - Fully featured free online PNG, JPG, TIF, BMP & GIF etc. to ICO converter from sohOpen.