This might be old to you, but a few months back I saw a show on History Channel. It showed how the Egyptians may have used kites to move their blocks and erect the oblisks at such great distances. The eventual conclusion was that a similar principle could have been used on the megaliths.
All one needs is a few people to keep the kites from running wild and enough rope with a support system to place the blocks with precision.
ping
You owe it to yourseif -- if you haven't done so already -- to do as I did in my #13, above, and view all the movies on Wallington's "The Forgotten Technology" website.