I have found an internet article on the archeological find I reported. Go to http://www.uncc.edu/jdtabor/crucifixion.html . This article contains some illustrations which contradict my original reply that the crucified victim was "squatting" - my reply was based on a news magazine article which I read when the find was originally made. Now the man in the illustration is portrayed upright, with his ancles nailed at the side and his arms tied around the crossbar. In Jesus' case, however, according to the Biblical narrative (John 20:25), even his hands were nailed.
I think what we have to remember, first of all, is that the archeological find is just one example out of thousands of ancient crucifixions - we don't know if it was truly representative or not. But even more importantly, the way the crucifixion is represented in religious art is highly symbolic. No one, not even the JWs with their Jesus hanging from an upright post, attempts to convey the horror of the crucifixion. We must grasp the difference between religous or symbolic "truth" and literal historical truth.
The early Christians realized, even before they started depicting it in art, that the death of Jesus had more significance to it than a mere historical report could convey. They would quote a verse from one of the Septuagint psalms, which was not in the original, but which read, "The Lord reigns from the tree." To them, Jesus had gained a great victory and began reigning even from the stauros. Similarly, with regard to the deaths of the martyrs, the Revelation states: "These are they which came out of great tribulation, and have washed their robes, and made them white in the blood of the Lamb." (7:14) Historically, the martyrs were covered with their own blood, but on a deeper level they were washed in Jesus' blood because they had joined him as victorious overcomers.
It would be a good idea to view anew the death of Jesus as portrayed in art (including the icons of the Eastern Orthdox Church) and to realize that it conveys more than just the historical reality. The WT realizes the importance of symbols - that's why it took away the Cross as a symbol to which the JWs could relate. They have their own set of symbols which convey a different view of spiritual reality.
Justin