Hepkat/Cedarjet et al: Here's my view, truncated yes, but it'll have to do for now.
I, for one, partly agree with the notion much of the Arab and Muslim world must come to the terms with the fact that Israel exists, and will not be going anywhere. Also, I think that it is perfectly acceptable to criticize Britain for partitioning its sector of the Middle East the way it did, because frankly they should have known it would have caused problems. But, I think the question that most are forgetting, but must be asked is this: "How could it have been done any better?" For a minute look at the dynamics of the situation in 1948 Palestine: The Jews are there. So are the Arabs. They both hate each other, and when the British leave, as they inevitably have to, there are going to be some potentially bloody problems, ie civil war sponsored by extremists, mostly on the Arab/Muslim side in the form of 3rd entities, but also from militant Jews who pretty much think vice versa of what the Muslim extremists think. So what do the British do? They partition the land, some for the Jews, and some for the Arabs. Obviously, the Zionist movement catalyzed the eventuality of this occurence, but I am confident that it would have happened anyway if Britain had not been inherently pressured so much by the Zionists. The partitioning of Palestine was by no means a perfect compromise, in fact it was a horrible solution, but, at the time, it was the best solution. The same thing goes for that other religiously partitioned debacle of a former colony...India.
Knowing this, I therefore conclude that the statement that Israel had/has no right to exist because of the partitioning of Palestine is exactly akin to saying that East and West Pakistan (now Pakistan and Bangladesh), and for that matter, India and Trans-Jordan itself. Britain partitioned it, it exists, it has a right to exist.
So, what were those who wanted to see the Jews out of Palestine to do now that they couldn't initiate civil war between the Arabs there and the Jews? Well, they just plain invaded the Jewish area. In my opinion, the invasion of Palestine was pretty much the only feasibly avoidable action that directly spawned the half-century of state-to-occupied area-to-state Muslim/Jewish conflict in the Middle East. After the 1948 war, both sides of the conflict could easily claim and even justify their actions, given the misgivings of the opposite side.
Addressing a few other points:
The Palestinian Leadership: I used to have a little bit of respect for Yasser Arafat and the Palestinian Authority, standing up for the Palestinians' cause and promoting it to the world. After the tenure of Ehud Barak as Israel's PM, that all changed. Barak and US President Clinton offered the most generous peace package to the Palestinians had ever been and probably would ever will be faced with. It gave them control over a state, which included Gaza, 95% of the West Bank, 50% of Jerusalem, the works. Plus, it even intended to address the problem of allowing Palestinians displaced by the many Arab-Israeli wars to come back to Israel. It was what what the average Palestinian wanted and deserved, it was what Israel deserved, it was what America wanted, it was what pretty much the rest of the non-extremist Muslim/Jewish world wanted. So, with this golden opportunity set before them, what did the Palestinian Authority do? They rejected it. They categorically denied Barak's attempts at giving the Palestinians their own state, which would pave the way for making complete peace in the future. They rejected peace. Now, I can't really find any reason to justify popular Palestinian aggression against Israel. It may be a harsh statment, but still, the fact remains: the Palestinian leadership, which the majority of Palestinians support, rejected their best hope for peace. It took no idiot to figure out that if the Palestinian Authority rejected this offer, thought too generous by a large number of Israelis, that Israel would shift to a more conservative position on the conflict. Unfortunately, it may be years before another opportunity such as this presents itself to either side. I can't say that I don't put most of the blame on the Palestinians' side.
American involvement in the Middle East: Yes, America supports Israel. What's wrong with that? It supports the Palestinians too. That's why it's the main 3rd entity in the peace process. It was the United States that played a major part in drafting the aforementioned peace proposal. George Bush, for god's sake, has even stated that he backs a Palestinian state. The United States recognizes Israel; it recognizes every other country in the Middle East. And all of these countries with governments, policies, and social cultures many times worse than Israel's! The US also gives billions of dollars of aid each year to Middle Eastern countries, and was the leader in the fight against Saddam Hussein, which was supported by most of the Arab/Muslim world. Only Jordan, Yemen, Sudan, Tunisia, and the PLO didn't support the effort to let Kuwait stay the 19th province of Iraq (source: Kuwait Information Office). In regards to American stationing of troops in Saudi Arabia (Osama's main gripe): I don't think the United States would be overly hesitant to go into Iraq again and depose Saddam Hussein if it recieved widespread political and military support from Europe and the Middle East. I already wrote something on wider American foreign policy; you'll find it in the "Why People Hate America" thread.
That's it...for now.