Chances are you don't wash your hands before using your computer. And, let's be honest, you've probably consumed a snack or two while pounding away at the keys or perusing your Facebook wall. So it probably goes without saying that your keyboard needs a good cleaning.
Once again, use a soft, lint-free cloth and a gentle cleanser. If you have an external keyboard, make sure you unplug it and take the batteries out if it's wireless. You should be especially gentle when cleaning the keyboard, as the keys can easily pop off with too much pressure or if a frayed cloth with loose threads catches one. It's best to clean the base of the keyboard one bridge at a time by holding down the keys on either side.
It is extremely important when cleaning a laptop keyboard to use as little moisture as possible, since the keys sit right on top of the main components of the computer's hardware and any excess moisture could drip down the sides of the keys and cause water damage. Once you've gone over everything with a disinfectant, go over it one more time with a water-dampened cloth to remove any excess cleanser that could damage the finish.