I've had some really bad experiences with some very popular shops here in Chattanooga, but I have had some really good experiences with others. It's easy to bash the LBS, man I've done it, but it isn't really fair to the good ones out there that are just doing there best to make a living and promote the sport.
Here are some example of what LBS can do better than any mail order co:
1) Cycle South, Blue Ridge, GA: I needed an OS bar for my new bike. I was in Blue Ridge for the wekend to ride and gave Sam a call to see if he had anything ( no one in Chatt did). No, he said, but he would pull one off a floor bike if I was cool with that. Cool?! He went to the trouble of pulling a bar, ordering a new bar, and then charged me retail...that is awesome service.
2) Same shop: No shop in Chatt could get me a der hanger for a Gemini. One shop jerked me around for three weeks before telling me they couldn't get it. On the off chance, I gave Sam a call as we were heading that way for the weekend. He had one, but he told me "Chip, Bro, the way you ride you are gonna need two. I'll pull one of a floor bike and replace it later".
3) Suck Creek Cycle, Chattanooga, TN: Took a wheel in on Friday in to have it trued and spoke replaced...hoped I could get it back that evening but wasn't optimistic. The guys in the shop were very cool, friendly, and told me they would do their best. Despite being swamped they got it for me that afternoon so I could make a Sat ride. Also, anytime I have been near that shop a few minutes before or after hours and someone was there, they have been very willing to open the door and do business. Very cool.
4) Mission Cyclery, Bonita, CA: Alas, this shop is no more- bought out by Performance. The Carol family, who owned this shop, were some of the best people I ever met. They, and the network of friends we built through their shop, brought my wife and I into riding and made our stay our west the time of our lives. It is unbelievable how many people that single shop brought into the sport.