After getting nowhere with his complaint (a damaged guitar), Dave Carroll and his band "Sons of Maxwell" decided to post a music video about the experience; you can guess the rest - the video was posted July 6 and by July 8, over 600,000 views and United had contacted Mr Carrol in order "to make things right".

United Breaks Guitars - video U-Tube

The story - LA Times

Update-- "Rob Bradford, managing director of customer solutions at United, called Carrol Wednesday to apologize for the foul-up and to ask if the carrier could use the video internally to help change it's culture."
Story - Chicago Tribune

And to think, this was only the first of a set of three videos.