Green Bee-eater

This one is really cool ....

...in the wings (and possibly even the body of the bird) is good, but the out of focus tree branch takes away the feel of flight, making one wonder how much is the bird's movement and how much is the camera's.

I think your shutter speed was just right, next time, use a tripod to eliminate the camera movement.

Having said that, I had the exact same problem (although much WORSE) in this image: http://photo.net/photodb/photo?photo_id=2933542&size=lg

Keep on trying, though. You've almost got it!

Your timing is OK. with 1/500 sec you should be able to get the body of the bird sharp when you follow the bird with your camera. Looking at the movement you were you somewhere between holding and panning.  Try to use a shuttertime shorter than 1/1000