Most people have Mint in a subdirectory like /mint. This is a problem if you want to set an iPhone favicon for your root domain, but change the favicon in subdirectories because the iPhone looks in the root directory for the favicon.
A joint effort over Twitter between Cameron and I to hack Mint to display the Mint Icon on your iPhone instead of a picture of your Mint page or the default WebClip you have uploaded to your root directory.
By “hack” I mean slightly edit, and by “joint effort” I mean I resized the 3 different colored Mint Icons to 57×57, and Cameron figured out the edit and wrote the tutorial.
UPDATE: If you’re still stuck with your site’s root folder’s WebClip try “Red X-ing” out of your Mint browser window, restarting your iPhone and then re-navigating to your Mint install.