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                                                         (CC BY-NC-SA 3.0) By C. Frank Starmer (Creative Commons)
Pretty cool image , right? This is an image of Sydney, Austalia. Here is how to create this amazing image with Photoshop!:

 INSTRUCTIONS: Obtain an image (google advanced search - labelled for reuse - make sure you get he license details and publish these on your website - see my example) of a building or skyline or a tree etc. - good to have these on the horizon with nothing behind.
It is best if both sides of the photograph end with the same subject e.g. field - this will make joining easy. However, we can change photographs with compositing/cloning too. Open photograph in Photoshop and edit with crop tool/clone stamp tool etc.
 You might want to make the sky as plain as possible. To do this you might have to select/copy the main subject from the background and paste it onto a new background which you can colour.
CREATING THE PLANET:
Open your edited photo, resize the image to 1000 px by 1000 px (uncheck the contrain proportions) This will squeeze the photo. Now flip the image upside down (rotate). Now go to Filter - Distort - Polar Coordinates - Rectangular to Polar. This will create the planet. You may have to go back and change things to make the image work - e.g. make sure that the sides of the photo match, resize the image differently (but always to a square).
Source: http://ischools.ccrsb.ca/m19/mod/assignment/view.php?id=27639

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                                                             (CC BY-SA 2.0)  By Michael Patterson (Creative Commons) 
Here is my second image of "Little Planets". As an image of a field , and using Photoshop, the final result is an intriguing planet-like image! The steps to make this I incuded in above's image , because the 'secret' to making these images mostly follow the steps! {Hope you like it!}
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                                                                                                     By jrossol (Flickr)
Here is my third image for "Little Planets". This image and above's image were slightly 'altered'. I had to make each image symmetrical by copying  (and pasting) both images on a New Blank File, flipping on horizontal and then sticking them together. I  followed the same steps as the other images!
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If you compare this image and above's image- do you notice anything different? Well, look at the top of the 'globe' see where in Pict.#1 there is the setting sun? And that in Pict#2 there is a building? I used (in Photoshop) the "Lassoo, or Quick Selection Tool".Then copy and paste. Next move your newly pasted object, and rotate to your choosing.