Scott may have an abrasive attitude, but he's right. I sell for VZW and see more damage done due to pocket carry than case carry as well. Not to mention all the pocket lint in charge ports, speakers, behind screens, etc. Snap-in holsters, on the other hand, are the worst. Phones have a tendency to be forcibly ejected from those
Also, many snap-in holsters have the phone facing outward and exposed, which is just asking for a good smack against a doorknob or something. A good leather belt pouch, like the OEM Blackberry ones, are ideal. Protip: The Storm with a silicone skin on it fits perfectly in the OEM Blackberry 8703 case. So does the Curve+skin.
Hip-slinging your cellie has become less goofy as cell usage has become ubiquitous.