When I bought my MacBook, I almost coughed up the extra money for a MacBook Pro. It wasn't because I needed discrete graphics or slightly faster processors. I had tried both MBPs and MacBooks and the MacBook was plenty speedy, light, small, and had outstanding battery life. Rather, it was because I hate glossy screens, and the MBP can be had with a matte finish LCD.
Alas, my budget didn't allow for the upgrade and, frankly, I simply couldn't justify the cost for the applications I use. The glossy screen phenomenon extends far beyond MacBooks, though. It is standard on virtually every mainstream laptop on the market. Sure, there are plenty of business laptops with matte screens (although they're becoming rarer as well), but these, like the MBP, tend to be pricey.
Thus, when teachers buy their own laptops or we start looking at tech refreshes, there is a decent chance that glossy screens will make their way into your classrooms. The better glossy screens really do have outstanding contrast and picture quality and glare is rarely an issue indoors anymore, but they tend to get incredibly dirty. As they are shoved into backpacks, squeezed under arms, and set under stacks of books, all of the oils and dirt from users' hands, lunches, etc, transfer onto them, often leaving permanent marks (my 17" HP has a 14" line corresponding to the location of the wrist rest).
Enter the ShaggyMac, a great product for both Apple and PC laptops. They double as microfiber screen wipes, but are heavy pieces of what feels like chamois, and lay over the keyboard when you close your laptop. They are relatively inexpensive (about $16, even for a 17" ShaggyMac) and really do work. Not only do they clean glossy screens well, but I have yet to find a mark on my new laptop screen.
I can now enjoy my glossy screen, and we can take advantage of cheaper, mainstream laptops, without worrying about the grime they tend to collect.