I must say I pretty much agree with miltiades on this one.
No mainstream religion preaches that the way to a better afterlife is to murder yourself and other innocent people, and the fact is that all these suicide bombers are doing is giving Islam a bad perception in the eyes of any non-Muslims out there. You may say these suicide bombers are brave, for being able to take these actions. No, they are not brave, they are cowardly. They lack a conscience and morals which naturally cause us humans to respect and value life - their own lives, and others. Their actions are inexcusable, and indefensible. Almost as bad, in fact, as those people who convince them to take these actions - people who, I am sure, are even so cowardly themselves that would not take their own lives for their "cause".
And now, they will look up from the deepest parts of Hell and wish they could influence others that follow them, and convince them not to do the same. But they cannot. It reminds me of the parable in the Gospel about the rich man & Lazarus (not sure exact details, my knowledge of Scripture is not so good)... the rich man looked up to Heaven and asked Abraham to warn his brothers not to make the same mistakes he did, but Abraham reminded him that if they would not listen to the teachings of Moses and the Prophets then they would not listen to him, or even change their behaviour if they were to see someone rise from the dead. So, these suicide bombers who claim they are devout Muslims.... I have not read the Koran, but we are regularly assured by Muslim scholars that nowhere does it advocate the sort of behaviour demonstrated by suicide bombers. Yet will they learn? No, they will not listen, their ears are blocked and their eyes are closed. Preservation of life, your own and others, is a fundamental basic concept of humanity, ergo these suicide bombers are not human. QED.
Pete