This type of live wallpaper isn't something new, there are few more wallpapers like this one on the Market, but I think that this is the best of them. It takes only 800 kb, it doesn't create any kind of lag on a 1 GHz Snapdragon processor, it looks great on Nexus One's high-resolution screen (480 x 800 pixels), and it seems that the battery drainage is extremely reduced. Your device must support Live Wallpapers, otherwise it won't work.
Search it in the Android Market: "Day of Ubuntu".
P.S.: I'm not using the native Launcher, that's why my dock looks like that.