Is it really all that surprizing that various symbol worshiping theological organizations have created or incorporated the simplest geometric design as a correspondence application. The circle or any pattern of intertwining circles have the obvious relationship to consepts such as zero, infinity and all the paradoxical phenomena inbetween. The Tree of Life is not a key to another dimension nor, does it contain hidden information, wisedom or, the secerets of the universe until of course, such information is discovered and understood, it’s only afterward that it becomes metaphorically related.
I don’t see anything extraordinary when pattern-seeking beings that use symbolism as a primary function for consiouss thought in a geometrically defined universe, use any basic pattern of geometry to define their surroundings. One can even impose completely illogical metaphysical nonsense to such symbols, that’s the beauty of symbolism, it’s not bound by laws.
As for crop cirles, I’m sure you can watch any one of several home-made crop circle videos on Discovery or History channel or even Youtube if you’d like to needlessly waiste your time as the creators of the circles did, if you need proof that they can easily be created by people in a brief period of time with different tools depending on which method the designers chose.
For those who say why would someone bother in the first place, my guess is it was probably somewhat entertaing for a group of friends to get high and call up the whole world and say “a is your refrigerator running….better go catch it, uha hehe haa!!!!