Base64 PNG Server
In my mind, one of the coolest things tht modern web browsers can do is deal with base64 PNG images. PNG images are the "new standard" in web images. They can be very small in size or they can be larger as true color images depending on your needs. They don't replace everything, but they do replace a lot.
A base64 PNG image is a PNG image encoded as base64. Base64 encoding is a way to encode non-printable characters (stuff you can't see, but the computer can read) into printable characters (things like letters and numbers).
Base64 PNG images (which are text) can actually be read by modern web browsers as real images. In fact, it's one of my qualification requirements for being a modern web browser (actually there are MANY requirements in my mind). You can actually use base64 PNG images directly in CSS. Here's an example...
background: url(data:image/png;base64,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);
Well, it's not SUPPOSED to be small! It's supposed to be embeddable. And it is. But think for a moment. You can take an image (not just PNG mind you, GIF can do this as well) and turn it into Base64. Now, can't you dynamically load images on the client? Well, yes you can... All you have to do is do a remote call to somewhere which will send the Base64 stream back.
One you get the stream back all you have to do is prefix the base64 stream with "data:image/png;base64," and assign the entire value to the src property (attribute) of an img object.
Here's an example I put together a few months ago of how you can do all this... Firefox users only please! IE6 won't get NEAR base64 images.
Actually, this is also a great example of how to work with web remoting (I just CAN'T call it Ajax, that's too weird) and how to dynamically work with XML files.