Very cool. I've seen this elsewhere on the web and I wondered who made it. You say "free to use," but I'd still like to ask permission for specific use. A non-commercial twitter bg just for myself. If not, still looks great on my icon dock.
The icon looks better fatter because if it was skinny there'd be all this blank space on either side of the icon, so in docks the icon spacing would be consistent. Of course I just made this up on the spot, but you know