Hygiene.  The second greatest achievement of humankind.  Cake is vastly superior however and shall remain the greatest of the divinely inspired gifts for all time.  This is not debatable.

Okay, those previous statements are over-exaggeratedly hyperbolic, but hygiene is important.  However, the moment a keyboard or mouse are introduced into someone's life, their prior respectable standards of cleanliness disappear.  It immediately becomes a surface to butter your toast on, collect all the crumbs from your meals at your desk, and catch the boogers you're skillfully prying from your schnoz.  The wretched hive of scum and villainy that Obi-wan was talking about was not Mos Eisley, but actually your nasty keyboard.  Okay, he was actually talking about Mos Eisley, but allow me to help you prevent your keyboard from becoming as disgusting as said nefarious spaceport.

1. Wash your hands.  Pretty easy right?  A surprising number of highly educated software developers just can't get their minds around this one.  Make a mental note of those people and avoid shaking their hands and using their keyboards at all costs.  It's also a great way to get the excess oil off of your hands so your keyboard won't wind up with that old keyboard shine.
2. Get your finger out of your nose.  There must be something instinctual that triggers people to immediately start digging for gold when looking at powerpoint slides, but it's nasty and inexcusable.  If you ever see a keyboard with a random green globule on it do not walk or pass go, but run the other way immediately...
3. Don't use your keyboard as a placemat.  Do you know how much bacteria is on there?  With your germ coated epidermis touching it all day the answer is a lot.  Like an 18 story parking garage lot size.  So don't help those microbes thrive by eating directly over it.  If you've got room in your cube, slide down a few feet and eat there instead.  If you don't have room in your cube, it's either time to ask for a promotion or look for a new job.
4. Clean up the crusties.  Crusties are those dark but crunchy spots that occur when you drool on your keyboard because your monotonous manager turned a fifteen minute meeting into three hours (please just be slobber and not other bodily fluids people release while browsing the internet).  Please take the 30 seconds to get a slightly damp cloth to wipe them up.  If another person were every to touch your nasty human interface device the crusty may try to eat them.
   
5. When it doubt, set it on fire.  A fantastic tenet to live by and most certainly applies to keyboards and mice in the workplace.  It's far easier to explain to your manager why your mouse is now a cute little plastic puddle than to explain to your insurance company how a keyboard devoured your left arm.  Requesting your supervisor purchase you a new device is another approach, it just lacks the grandeur that a modern office requires.
   

So there you have it, extremely simple steps to help you not catch Syphilis-of-the-keyboard or other human interface device transmitted infections (HIDTIs for all you stylish people with your fancy abbreviations).  Not only will you be healthier, but your coworkers will stop looking at you like your forgot your deodorant... You did remember your deodorant right?

Oh yeah, and that part about cake, that's all true.