Im sharing this because i find it pretty awesome i know you can easily install a theme on other media players but this can use PSDs all you do is drag and drop the file on the media player and the skin will change its pretty good im trying to look more into it and if i get far enough i will make a 360haven skin for the player but i dont know yet if you guys like it the download link is below
http://xion.r2.com.au/
You can download themes from the site aswell or from deviantart
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With a skin i downloaded