Flying in Seattle 

A helicopter pilot is flying to Seattle, and hits a pea-soup-thick fog bank. He' s completely disoriented, and flies blindly around until he spies the top few floors of an office building . He pulls up real close to it, and gets the attention of a woman sitting at her desk. 

"Excuse me!" he yells. "Where am I?" 

"You're in a helicopter," she replies. The pilot pulls off sharply to the left, takes one or two crisp turns through the dense fog, and then does a perfect blind landing at the Seattle-Tacoma Airport. 

"That was amazing!" says a passenger. "How did you know from her answer where you were?" 

"Easy," says the pilot. "Her answer, while correct, was absolutely useless. So I immediately knew I was at Microsoft Tech Support."