"STAUROS ... denotes, primarily, an upright pale or stake. On such malefactors were nailed for execution. Both the noun and the verb stauroo, to fasten to a stake or pale, are originally to be distinguished from the ecclesiastical form of a two beamed cross. The shape of the latter [the cross] had its origin in ancient Chaldea [Babylon], and was used as the symbol of the god Tammuz (being in the shape of the mystic Tau, the initial of his name) in that country and in adjacent lands, including Egypt. By the middle of the 3rd cent. A.D. the churches had either departed from, or had travestied, certain doctrines of the Christian faith. In order to increase the prestige of the apostate ecclesiastical system pagans were received into the churches apart from regeneration by faith, and were permitted largely to retain their pagan signs and symbols. Hence the Tau or T, in its most frequent form, with the cross-piece lowered, was adopted to stand for the cross of Christ." - W. E. Vine, p. 248, An Expository Dictionary of New Testament Words, Thomas Nelson, Inc., Publishers. - Also see "Cross" in Reasoning from the Scriptures and "Torture Stake" in Insight on the Scriptures (Watchtower publications).
Also see:
Cross - Links to Information (Defend Jehovah's Witnesses)
NWT - Criticism by Zondervan's So Many Versions? - "Torture Stake" vs. "Cross" (DNWT)
Extracts from HISTORY OF THE CROSS: THE PAGAN ORIGIN AND IDOLATROUS ADOPTION AND WORSHIP, OF THE IMAGE. BY HENRY DANA WARD, M.A., U.S.A. 1871 (INDNWT)
The STAUROS of the New Testament: Cross or Stake? (INDNWT)
Advantages of the New World Translation: Did Jesus Die on a Cross? (JW United)
Cross or Stake (Stauros) (pastorrussel)
What does the original Greek reveal as to the shape of the instrument on which Jesus was put to death? (JWQ&A)
If Jesus was nailed to a tree with his hands above his head then why does John 20:25 say nailS? (Y/A; Esp. Bar Anerges' response);
Jehovah's Witnesses were not the first nor the last to believe that both Greek 'stauros' and Latin 'crux' originally meant stake or pole. "Little Evidence Jesus Died on a Cross, Says Scholar" - AOL news article
"Jesus did not die on cross, says scholar" (News article from Telegraph.co.uk)
NWT - Criticism by Zondervan's So Many Versions? - "Torture Stake" vs. "Cross" (Defending the NWT)
Quotes concerning the pagan history of the Cross (SFBT)
Should the Cross be venerated? (JWQ&A)
Does it matter if Jesus died on a cross? (SFBT)
The Sign of the Cross (pastorrussel)