As a prequil to an upcoming tutorial I'd like to put this software up for review. It's freeware and as far as I can tell the best of it's kind.
It enables you to easily create and save icons for Windows (and recently Mac). Though, if your making standard 256x256 icons I suggest using a secondary image editor like Photoshop or Paint to manually resize before pasting into Greenfish.
Anyone with a spare moment, look it over and give some feedback!
http://download.cnet.com/Greenfish-Icon-Editor-Pro/3000-2193_4-10773415.html
Note: Pay attention during the install, Cnet likes to include toolbars and homepage changes. Just opt out by unchecking boxes or not agreeing to terms.