Waiting for a website to gain a WebClip icon? There's a load of sites available to either help you find an icon that's already been made -- such as WebClipMe! or the WebClip directory. clipalizer goes one better, allowing you to upload your own (correctly sized) PNG image and then use that as a webclip icon.
So how do I create my own WebClip icon? A WebClip icon is basically a 57-pixel-square PNG image called apple-touch-icon.png placed at the root of your server's web-content directory (though the Apple Developer Connection site lists a way that code-savvy users can specify a custom location for it, should they so choose). Whilst the icons appear rounded on the iPhone, you don't need to worry about creating curved corners, or even apply a button-esque mask in Photoshop: iPhone takes care of all of that -- "Safari will automatically composite the icon with the standard "glassy" overlay so it looks like a built-in iPhone or iPod application."
Thanks to all those who sent us pleading emails!