I heard about this on the news and thought it was pretty interesting. Apparently, British classrooms will be required to show a disclaimer about Inconvenient Truth if they show it in class, stating that it is politically biased and contains possible inaccuracies (link - http://www.upi.com/NewsTrack/Quirks/2007/10/03/teachers_to_warn_pupils_about_truth_bias/6597/). I think it's a fair way to handle showing the film in a classroom setting. It shouldn't be flat out banned from classrooms, but people should certainly know the ideological viewpoints of the people involved. That's pretty much a must for anyone reading/viewing/listening to anything designed to transfer information. Context is so important and often overlooked.