During the 90′s, when cell phones were becoming all the rage, the belt clip for phones became a status symbol of sorts. Since phones started out so large that they wouldn't fit in a pocket, clipping them to a belt (or hiding them in a fanny pack) was an acceptable way to transport them. Even today though, when a smart phone is thinner than a pack of cards and not much larger (in many cases), some people prefer to have their phone clipped to their belt. On cooler days when I wear jeans to work, I usually use a belt clip for my phone, since my work shirt has no pocket.
The Gadgeteer , Cellet iPhone 4x4s belt clip review, Cellet iPhone 4x4s belt clip review