A new crop picture from Rho, Italy on April 26, 2008 seems to describe a total lunar eclipse which happened two months earlier on February 20, 2008, and could be seen across most of our planet

Many simple dumbbell-type crop pictures use an ancient astronomical symbolism that was originally written down by Ptolemy in Egypt 150 AD,  to tell us about recent events in Earth's sky contemporary with their appearances:
 see for example www.cropcircleconnector.com/anasazi/time2007f.html. Some of those ancient symbols are still used today in the art of natal astrology, especially the symbols for "conjunction" or "opposition" (see http://en.wikipedia.org/wiki/Conjunction_%28astronomy_and_astrology%29 or http://en.wikipedia.org/wiki/Opposition_%28astronomy%29).  

During any lunar eclipse, the large bulk of planet Earth comes between our Sun and our Moon as a kind of conjunction. That particular kind of astronomical event should therefore be symbolized by a single-ended dumbbell symbol for "Moon", overlaid upon an open circular symbol for "Sun". And that is what appeared in crops on April 26, 2008 at Rho, Italy. If real and not human-made (details suggest the former), then it may have been made to mark a total lunar eclipse that occurred two months earlier on February 20, 2008:

Many best wishes to Alessandro and Andrea, who provided excellent field data and photographs! The "small clockwise circle" within a "large anticlockwise circle" as shown there probably represents a "small lunar disk" fitting inside of "Earth's large shadow": see above. Two standing tufts at the centre of the large circle may mean "Earth and Moon come together". Alternatively, they could symbolize when the lunar eclipse began and ended: see above (red part only). Further study with this general model in mind could prove useful.  

Astronomy is a universal kind of knowledge, easily interpreted by capable scientists on almost any world. That is why, I believe, that so many of these early SETI-type crop pictures have shown simple astronomical themes, in order to establish a preliminary dialogue from which we can go further. Various media organizations claimed in the early 1990's that such dumbbell-type crop pictures had been made by two old guys from the pub, "Doug and Dave", using a rope and boards! Their unfounded claims now seem even more doubtful, since those two old fellows would have been practically astronomically illiterate.