We had a nice clear and windless morining and I photographed sunrise hoping some mirage would form. The direction of the rising Sun there is a cold valley where fog usually collects so it is a location colder then its surroundings. When Sun rises there it is likely to get a distorted image of its disk because of the inversion layer at the valley.
The image I saw when Sun appeared was incredible! This was the strongest mirage effect on the Sun I have ever seen! (Similar effect works at the Californian coastline where the cold California current is responsible for the mirages.)A bit later the distortion reached the region where the big sunspot #1471 is located as a well visible dark dot, I saw the sunspot disappearing and appearing again, then its mirage appeared above the original spot higher on the solar disk, then a third mirage-spot appeared... I was shivering with beauty! It only lasted about 3-4 minutes but it seemed to be a century for me!
I have a short animation of the effect on the sunspots: http://youtu.be/0vz03soHUqo
Nikon D5100 with 55-300 Nikkor lens @ 300mm