Yes, they are the same. Surely, you know that even that Pope John Paul II said they were the same. If they weren't the same, why did Allah send Gabriel, an angel of Jehovah, down to Muhammad?
Allah is god
Allah is arabic for god
Christian arabs use the word Allah
You lose
Allah is Arabic for God.
So the Muslims are worshiping God, the Christian and Jewish God. The 3 religions are the same, just have different beliefs on the prophets. Nothing about which god they worship.
Allah, Jehovah, God, all the same.
Stop being a bigot candle
Edit: Crosspost with AlCosta and Stylesjl
This is all a bit of a superficial take on it. Yes, even Arab Christians use the word "allah" for God, but there is a major difference in its usage. Muslims identify this as a personal name for God, whereas the Christians are using it as more of a title. It gets confusing.
To address the first statement, calling Allah Jehovah/Yahewh does not make it so. Just because Muslims say that Allah is the same as the others does not mean we are compelled to accept this answer. (I suppose we can turn that argument around, too.)
Beyond the name, there are important differences in God's nature among the three, but particularly between the Judeo-Christian tradition and Islam. To say that there are only differences of prophets makes it sound more like the ancient syncretic polytheists; the Greeks and the Romans identifying their gods of war comes to mind.
The Koran portrays the Christians as polytheists because they worship the Trinity. "They do blaspheme who say: Allah is the third of three." There is evidently some sort of difference to them.
However, let me quote here from another site I found about this issue:
"Muslims believe that Allah of the Quran is the same as God the Father of the Holy Bible since they do not believe in God the Son, Jesus Christ, nor in God the Holy Spirit..."
So they do want to identify Allah as God the Father, yet they regard Christian beliefs as heretical. The real point of contention, I suppose, comes in the nature of the Trinity and the person of Christ. But beyond this there are fundamental differences in the character and nature of Allah and Yahweh, which are far too complicated to address here.
Now, I believe you can successfully argue that the Jewish God and Christian God are, historically, the same. The difference here is that their natures (aside from trinitarian issues, though that's a very important distinction) are quite similar, and you cannot necessarily say the same thing for Allah and Yahweh. We also get into alternative histories, different kinds of involvement in human affairs, etc.
My point is that it is too simplistic to say that all are worshipping the same God. If you are going to identify "God" simply as the ruler/creator of the universe, then yes, we can say that they are all the same -- and probably half of the other religions of the world, too. (My, aren't we all just one big happy family...) But if you're going to lay out details about God's character, his personal attributes, role in the world, commandments, etc., then we start to run into problems.
Somebody else put it this way:
"So often the question is put to me "Is Allah the God of the Bible?" Too often people are looking for a simple "Yes" or "No" answer..."