US Patents and Trademark Office has today made public a Microsoft patent application (serial no. 240,729) related to the graphical user interface found on the hotly anticipated Windows Phone 7 Series mobile OS. Filed in September 2008, this application describes a "contiguous background" that extends beyond the dimensions of the screen (either vertically or horizontally, but not both) with anchored "mixed-media" elements being littered atop it -- all of which is to be served on a "media-playing device." That should sound pretty familiar, given that it's the central navigational concept of both Windows Phone 7 and the Zune HD, and as such it makes a lot of sense for Microsoft to seek to legally protect its uniqueness. Before you start wondering about potential conflicts with other UIs, take note that this requires a continuous graphical background rather than a tiled or repeating image, plus space-orientating graphical elements, which should make it sufficiently nuanced to avoid any more patently unnecessary squabbles should Microsoft's claims be validated by the USPTO.