I was checking out podtech.net after reading about it on Robert Scoble's Blog and found an interesting video about Southwest airlines. They decided to use a group blog as a marketing tool. Nuts about Southwest is a blog that several southwest employees, and a few customers, post random bits of Southwest info. The blog has lots of interesting insight into a very complex industry.
The coolest post on the main page (on a side note what is it with some blogs not having a next/previous button on the main page to see more post, that always makes me mad) is about new airport power stations. I don't fly much but when I do I hate walking around the airport looking for a plug on the side of a pole or on the floor. The comments point out a few design flaws in the stations, which goes to show how a company can use a blog as an interactive medium with its customers.