Using Social Media as a conduit for customer service scares a lot of companies. Sure, you'll get props from the people you help, but what if customer complaints and abuse outweigh the number of resolved issues? This attitude is way too prevalent, so it's important to recognize the companies who do respond well to their customers.
Nola.com (@NOLAnews on da twittah) is the on-line source for the Times-Picayune newspaper. I'm following a story on taxicab drivers in New Orleans for my travel blog, YatTravel, and I wanted to reference a story I read this morning, but couldn't find it on-line. I found it curious that it wasn't listed in the "headlines" section, and tweeted that frustration.
Within minutes, I got back an offer of help:

A while later, I got these:

and when I thanked "LWL," I got this:

Now THAT is customer service! I pick on @NOLAnews a lot, because there are a lot of flaws to NOLA.com, so it's important to give credit when they do good. And this is doing better than just good.