I think a lot of this is overhyped. On Wikipedia's autism article, it has a kid stacking food cans http://upload.wikimedia.org/wikipedia/commons/d/d1/Autism-stacking-cans_2nd_edit.jpg and it says "Repetitively stacking or lining up objects may indicate autism." Wow. Simply stacking items may be a sign of autism? That is simply curiosity, or a love for building.
That is one thing many children with autism do. Does it mean every kid that does this is autistic? NO. Its just one of the many signs of autism. My son loved to line up cars and movie boxes. he would also play with the light switches for ever. Our favorite was watching him stand in fron tof the tv and act out the show ( he was obsessed with certain movies and cartoons and would reenact the whole show while it was on )
Thank God (take that karma!)