Many of the icons are works of art when viewed at their full size. The TextEdit icon, for example, is actually a note from "John Appleseed" to "Kate" featuring the text of the "Here's to the crazy ones" ads of the late 1990s. The Jar Launcher app, featuring a cup of hot Java sitting on a paper napkin, reveals miniscule bubbles on the side of the coffee, as well as real Java code written on the napkin.
All of these icons are indications of the fanatical attention to detail of Apple designers. After looking at Kahney's gallery of art, I gathered my own collection of icon goodness from both Apple and third-party apps. Click the gallery icon below to see what I found. If you have found any 512 x 512 icons that are incredibly good, send 'em to us at http://tuaw.tumblr.com/submit.