office space of the day... art wall ideas

mod desk + beautiful blue chair + sculptural lamp + bar cart office tray + mix of artwork=
domestic bliss
I have slowly been creating a beautiful home office for myself. I finally found the perfect desk to fit in my apartment. It's black and glossy with the most beautiful legs. (i will put up a pic soon)
So now, I am looking for the perfect way to dress up the wall space above my desk...
and I love the way these collections of great pictures look above fabulous pieces. 
All black frames with white matting looks divine, but mixes of gold frames is an old favorite too! 
Curious to know what you guys have above your desk....? I'm would love some fun suggestions.