http://www.bruceleibowitz.net/mystery_contrail.jpg
I was thinking this could be JetBlue, because it has a blue belly, blue engines, and white sides that sweep down under the tail. But is this really an A320?? It was over Nashville heading east in late afternoon. but Jetblue doesnt have any routes at that time near that area.
do you think it could be a Triple-7? Think of British Airways:

Photo © Sid Star
BTW, this is an awesome photo IMO. But, it also has a blue belly, blue engines, and white sides that sweep around under the tail just foreward of the horiz. stab. - very similar to Jetblue.
I'm not saying it is this exact jet - mine doesnt have any red near the tail. I merely picked this shot to show the BA colors. Not all BA 777s have red like that you know.
Look at the underside of the wing on the BA. It appears to be two shades of grey. Mine also has two shades of grey! Also, and I dont know if this means anything, but check out the contrails on both. The right engine has a wider contrail on both!
If this is a 777, then I think it would have to be BA. And there are several flight possibilities - it could be coming out of DFW or IAH.
Now see a Jetblue:

Photo © Jonathan Icasas
Look under the wing; I do not see two shades of grey. Also, most of the JetBlue planes seem to have blue tails and mine does not. Are there any JetBlue's with white tails? I also think the engines of mine are "fatter" than the slender Airbus engines.
What do you all think?
bruce