Icon files are not a standard graphics format. To comment on Dreamer101's comment - 16x16 isnt quite what it was: That was the old desktop icon size in earlier versions of windows, but this has changed. The ICO format is actually a container for a number of icons at different sizes and resolutions, that can be used in different modes, ie: in XP, the desktop icon is more detailed than the mini version on the shortcut bar or tray. Macs have a similar concept. There are a number of packages available, some for designing and exporting, whilst some are editors only. There are even some as PS plugins. Hope this helps.