Before the early Christian church, what were other uses of (versions of) the cross? (As a symbol)

Ancient Babylonian religon used a cross like symbol in the worship of the pagon god Tammuz(note the "T"), the early church adopted many pagon symbols/ideologies into its church the cross was just one of them

There is much historical documentation of the use of the cross before Christendom adopted it: (Sources cited)

“Various objects, dating from periods long anterior to the Christian era, have been found, marked with crosses of different designs, in almost every part of the old world. India, Syria, Persia and Egypt have all yielded numberless examples . . . The use of the cross as a religious symbol in pre-Christian times and among non-Christian peoples may probably be regarded as almost universal, and in very many cases it was connected with some form of nature worship.”—Encyclopædia Britannica (1946), Vol. 6, p. 753.
“The shape of the [two-beamed cross] had its origin in ancient Chaldea, 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.”—An Expository Dictionary of New Testament Words (London, 1962), W. E. Vine, p. 256.
“It is strange, yet unquestionably a fact, that in ages long before the birth of Christ, and since then in lands untouched by the teaching of the Church, the Cross has been used as a sacred symbol. . . . The Greek Bacchus, the Tyrian Tammuz, the Chaldean Bel, and the Norse Odin, were all symbolised to their votaries by a cruciform device.”—The Cross in Ritual, Architecture, and Art (London, 1900), G. S. Tyack, p. 1.
“The cross in the form of the ‘Crux Ansata’ . . . was carried in the hands of the Egyptian priests and Pontiff kings as the symbol of their authority as priests of the Sun god and was called ‘the Sign of Life.’”—The Worship of the Dead (London, 1904), Colonel J. Garnier, p. 226.
“Various

A sword? Just guessin' here.

Big Clue- they were a symbol of Crucifixion. A nice and tidy little reminder to any slaves thinking of freedom.

http://en.wikipedia.org/wiki/Christian_cross#Pre-Christian_cross-like_symbols

Got Ankh?

The would not be one. The cross is the basis of Christianity.

The early Christians used a fish as their symbol. This is because they could not stand openly under a common banner for fear of persecution. When a Christian met with another Christian, one would draw the fish in the ground to see if they other recognized what it meant.

The fish (Ichthys or ἰχθύς in Greek) was an acronym for Jesus.
- Iota (i) is the first letter of Iēsous (Ἰησοῦς), Greek for Jesus.
- Chi (ch) is the first letter of Christos (Χριστóς), Greek for "Christ" or "anointed".
- Theta (th) is the first letter of Theou (Θεοῦ), that means "God's", genitive case of Θεóς, Theos, "God".
- Upsilon (u) is the first letter of huios ( ͑Υἱός), Greek for Son.
- Sigma (s) is the first letter of sōtēr (Σωτήρ), Greek for Savior.

In short, Ichthys (ἰχθύς) stood for "Jesus, Son of God, Savior."
As far as I know, they didn't start using the cross for a while...