An employee arranges Apple iPhone cases at the D-Parts stand at the Internationale Funkausstellung (IFA) 2012 consumer electronics trade fair in Berlin, Germany.

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Smartphones: We love them; but man, do we do some dumb things with them. According to a survey commissioned by T-Mobile, nearly half of all smartphone owners have had their phones lost, stolen or damaged. For smartphone owners who have damaged their phones, 37 percent scratched the screen, 29 percent spilled a drink on it, 29 percent dropped it down the stairs and 20 percent dropped it in the toilet (ewwwwww!) [source: Kelton Research Smartphone Protection Survey].

Protecting a smartphone with a case is a no-brainer for a lot of smartphone owners. Other smartphone owners, however, don't think smartphone case protection is all it's cracked up to be. For one, no smartphone case -- or at least not one you'd want to carry -- can completely protect your phone from damage. Smartphone cases also add bulk to the phone and can hide cool aspects of the phone's design. If you're not super careful, a case can even damage your phone. Dirt and debris can get caught between the case and the phone and scratch the phone's finish. The smartphone cases that offer the best protection can be expensive, especially since you usually have to get a new one each time you get a new phone. Finally, smartphone cases can interfere with docking. It's a pain to have to take your phone out of its case every time you want to hook it up to your car or home stereo.

On the other hand, there are a lot of good reasons to use a smartphone case. If you're good about keeping it clean so dirt and grime don't build up between the phone and the case, a smartphone case will usually do a good job of protecting the phone from scratches. A smartphone case can also provide some protection if you drop your phone (though you shouldn't use a case as an excuse to launch your phone off your roof). Though a smartphone case may not make your phone look quite as cool, it can help keep all parts of it working. Dropping a phone may not result in much visible damage, but without a case it's easy for the smartphone's camera lens to get broken. Plus, with some smartphones having sleek-but-slick-finishes, a grippy case can help keep you from dropping the phone in the first place. There are a few waterproof cases on the market for smartphones, but even most basic cases should buy you a few extra seconds to grab your phone out of the path of an expanding puddle of spilled beer (your friends are such lightweights).

So, do smartphone covers really protect phones from damage? To a degree, they do -- but you still need to be smart about how you take care of your phone. I recommend not using it anywhere near a toilet.