A shot taken near Tentsmuir Beach in Fife (below) was given the 'little planet' treatment using Photoshop.
Full step by step details of how to play around with making these is in the group page below. I'm linking to the group page, as I'm sure the 'specialists' for this type of thing will have discovered other variations to try beyond the straightforward type I did above: www.flickr.com/groups/createyourownplanets
The planet making bit is very quick manipulation and you can immediately tell whether you feel it's something that you want to invest time in 'joining up' the edges of or just delete. It's disguising any 'join' where the time is taken up with these, which is why it's best to find something that will work as well as possible in the first place.