The dragonfly is one of the Pennants. If you want to try and narrow the ID, you might want to start at http://bugguide.net/node/view/523/bgimage?from=0 and work your way through them. Good luck. Nice shot!
The behavior is called an "obelisking". The tail will usually point in the general direction of the sun in an effort to reduce surface area exposed to the sun, thus reducing heat loading.
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