Inspired by the little dragon sig game I've been playing, I was thinking about a service that would allow one to register for a "morphing" avatar. The idea would be that you'd register and get a link to a gif, and the more views the gif got, the more the image would grow and change. For example, you might start with a seed, which would sprout, then put out a few leaves... and eventually you'd have a forest with trees, and perhaps a few unicorns or something.
There could be a number of different base images, and a certain amount of randomization in which elements would get added, so hopefully everyone's avatars would each be at least somewhat different. You could use this remote avatar on any online forum or blog that allows remote avatars.
The "karma" part comes in this way: ideally someone could click on the avatar, and add karma to it, just as we do here at MR, but I don't think most forum software will allow us to make the avatars clickable (or allow any other fancy scripting). So there would be a link to put in your sig line like "Click here to help my avatar grow", and clicking it would take a viewer to a page where they could add karma to that user, possibly in different categories. Visitor karma would make an avatar grow more than just repeated views. But the cool thing is that anyone visiting from any site could add karma, and it would display wherever your avatar displays.
It was just a little mental doodle I was thinking about as I was dozing off last night, but if anyone else likes the idea, I might pursue it....