The picture you posted was one of a few 'chemtrail' plane pics discussed @ AboveTopSecret
http://www.abovetopsecret.com/forum/thread361608/pg1 the conclusion if I recall correctly without rereading the full thread was that it is a photoshopped version of this
http://www.airliners.net/photo/Boein...-LR/0855967/L/
That being said - I firmly believe someone is spraying our skies for some reason....