I'm gonna try covering my lens hoods! I just ordered two sheets of 3M's DiNoc Carbon Fiber from this site:
I got one sheet in white and the other in gloss black -- white to complement my white lenses (70-200 and 100-400), and black for the rest.
I would respectfully disagree with my friend Ben_r.... the skins do protect the lens hoods from scratches and scuffs, all while adding a little personal customization. I have similar skins on my iPhone, as an alternative to a bulky case. Just my preference.