img2icns – Instant Drag & Drop Icon Creation
Here is a great little app that works exactly as advertised, creating icons instantly with just a matter of dragging and dropping an image file on the program. Whether you want to create icons for personal usage, desktop customization, or you’re a developer and you need an icon for the latest shiny cocoa software you are working on, img2icns works flawlessly. It doesn’t get any simpler than this, and the app is totally free.
Works wonderfully, as you can see in this picture it created a perfect scalable icon from a horrible graphic I conjured in Photoshop (in case it isn’t obvious, its the ugly blue O). img2icns is not a miracle worker however, so if you want the best looking OS X icon possible be sure to use transparent PNG’s as the icon source image.