This is simple. Only clean your laptop/LCD screen with the right cleaners. The liquid should be free of ammonia, the cloths should be soft and preferably made of microfiber. If you are using a static based duster for your keyboard and desk, make sure the computer is turned off before you clean with the duster. Small vacuums with low power are good to clean dust from under a keyboard (and not pull off the keys).
If you are finding that you need to clean too often, you probably have the wrong equipment. Your keyboard might be the right equipment for you at home, but the wrong choice for a class. Get a new silicone keyboard or cover, cheap covers for laptops or a case for your portable gadgets. You can get screen protectors for laptops and UMPCs, iPods and cell phones. I have only listed a few on the shop, as there are literally thousands of products in this category. Feel free to contact us and we'll send back details via email of a product and its price.
Some offices use canned air, which they spray into the keyboard and air at high speeds pushes out the dust. You need to know that the propellant in those cans is actually a drug with high levels of community abuse. It’s regular availability and largely unknown status has made it easy for people to buy it guilt free from a range of office supply shops. It came to the public attention through an episode of the TV series “Intervention” and an internet-fad remix of the episode into the ‘Walking on Sunshine’ hit from the 1980’s. Only Google that if you have a strong disposition.