For about the past four years I've used a piece of fabric covering the keys of my laptop to protect the screen on my Mac Titanium laptop. Its a fabric remnant of a tote bag I was going to make but of course never did. I just liked it because it infused a bit of color with its pale spring mix of blue, pink, yellow and green all formed in a stripe pattern. It was something cute that I liked when I opened up my laptop. I had seen the other guys at the tech conferences with their rubbery plastic keyboard cover in a thick mustard hue which looked as if like someone had just poured rubber cement into a mold. Sure it protected the screen from my oily fingers, but it was just plain boring.
iSkin the makers of iPod and Shuffle protectors, actually have Laptop keyboard protectors as well. They come in these variety of colors so that you'll never think "boring" when you open your laptop. Also, you'll be protecting your keyboard from dust and dirt build up. I'm definitely throwing away the o' piece of material and getting myself one of these.
There are also keyboard protectors for regular and wireless keyboards as well.