You mean like this Pi sign I captured yesterday?
http://picasaweb.google.com/kennyg357/Chemtrails41141210#5459348351632074002
They only lasted a minute or two. Almost made me think they where contrails.

Yesterday they also made these clouds which almost look real.
http://picasaweb.google.com/kennyg357/Chemtrails41141210#5459348347389254146

Today I was watching them spray at work and the plumes did only last a minute or two but it was constant spraying for six hours. My throat feels like there is a needle stuck in it and I have a bad headache again. When I got home I grabbed my camera and the spraying took a turn. The plumes are rapidly expanding and fading quickly as in this photo.
http://picasaweb.google.com/kennyg357/Chemtrails41141210#5459348356879414386

In no time the entire sky was covered in a haze like on a hot humid day except the humidity is only 36%. I tried to capture the haze in this next shot. Right now the sky is completely white. There is also a chemtrail streaming across the photo from the bottom right corner to the top left corner which is disappearing quickly too.
http://picasaweb.google.com/kennyg357/Chemtrails41141210#5459348359578896018

It seems like they are doing all kinds of different types of spraying.