Now a days we have tons of themes and skins to make our devices look like the HTC Touch diamond , here is a good Media player Skin from poorlyduck from xda-dev.

Instructions:

1) Create a new folder for your mediaplayer skins ( My device/program files/Windows Media Player )
2) Unzip the file and and drag the content to the new folder
3) Open windows media player, u dont have to play anything just click ok and go to menu/options/skins tab, let it search for all the skins available in your device and pick this skin, make sure you do this in portrait and landscape.

If you find this tool useful, please donate to the developer.

Source : xda-developers.com
=== DOWNLOAD===

Diamond WM Skin

Tags: cell phone, freeware, HTC Touch Diamond, media player, Mobile, PDA, Pocket PC, PocketPC, PPC, Skin, Touch Diamond, TouchFLO, Windows Mobile