To become a bit offtopic: Some people like 3D realtime rendered anti aliased 32bit true color diagrams spread over 25 layers. I prefer 10 elements, 3 colors, 1 font, 2 font styles and everbody gets the story's gist. Not a fancy on, but usable (and I won't need Tera Flops to render *g*). Additionally my favorite:
a rackmount server that doesn't look like a sun.
I agree. Look at the top diagrams on this page, for a glimpse how good things can look.
http://www.ratemynetworkdiagram.com
http://www.ratemynetworkdiagram.com/?i=124