When space is at a premium, you have to find different ways of maximizing what space you have. If you have high ceilings, then you should seriously consider using a loft desk, if your room doesn't have enough space for a bigger desk. This is what Joel Vardy did in his room. His desk/bed has got integrated speakers, wiring, and storage.
The storage setup is also pretty great. He can stash all of his gear easily enough. On the other wall, he mounted his HDTV coupled with his PS3. The height is perfect to play either in bed or while sitting in his Kawasaki Paddock chair.
The cable management includes holes in the three corners of the desk, as well as a fourth in the center, where the wires from his two 22" monitors and other peripherals disappear into. His room was painted white, the same color as the loft bed. There is an accent wall painted green, which adds a nice touch of color. Checkout the photos of his build over at his Flickr site.