I rather like this little ap from the folks at Skoop, called Twitter Mosaic.
Graphicly, it's got a rather pleasing passport-style 'ordered chaos'. Plus it's brimming with 'CafePress' potential (which is exactly the upsell it's targeting, I rather like the mugs). Our icons are individulal bits of art in their own right, personal enough for us to use them to represnt us to the world. Displaying them like this is quite a slice of society. I'm sure this could have further creative uses.
-mosiac removed as it was full of broken images once folks changed their pictures-
It's also good to see those black squares, where my friends and followers (above) are showing their support for NZ Creative Freedom :-)