The subject of God's name is quite confusing..!
After reading Will's post I recalled this passage in the Bible. It suggests that the name of God is "I AM".

Quote Originally Posted by Exodus
13 And Moses said unto God, Behold, when I come unto the children of Israel, and shall say unto them, The God of your fathers hath sent me unto you; and they shall say to me, What is his name? what shall I say unto them?
14And God said unto Moses, I AM THAT I AM: and he said, Thus shalt thou say unto the children of Israel, I AM hath sent me unto you.
I believe that Christians, Jews and Moslems worship the same God, and as far as I am aware the Islamic name for God is "Allah" - where does that come from ?