A while ago I posted a fairly critical review of the abuse of the Skype PowerPoint template. The first sentence of my post however was: "Skype has a beautiful and very strong visual identity".
Spot on. Browse through this document with guidelines for creating documents in the "Skype look". You can learn from it even if you are not designing for Skype. Beautiful graphics. Nicely written to give you directions but leaving you enough creative room to make your own designs.