Who isn't a Monty Python fan? Just got it on DVD, and boy am I satisfied! "Now you see that violence is inherent in the system! Help! Help! I'm bein' repressed!"
Anywho, about the Grail...It is true that it is Celtic mythology melding with Chrsition theology, but that doesn't mean it's impossible. I doubt that man will ever find the Grail if it still exisits on this earth and I doubt that Arthur and his knights would actually have found it and hidden it or sent it to heaven, I feel the same way about the Templar.
However, I believe something for nothing is supported by Christianity. Miracles are also reputed to happen to bad people, converting them. They do nothing, but they are saved. The true cross is said to have raised a man from the dead. He did nothing, in fact could do nothing, because he was dead. Yet he was raised by this artifact. I believe the stance of Christianity is "You'll get it in the end." Saints, prophets, or whoever you believe in, rarely lead happy and full lives. Often they are martyred in horrible ways. St. Sebastin was shot with many arrows only to live. He returned to the man who tried to kill him and tried to convert him. Sebastin was then beaten to death. And that's one of the happier endings to a Saint. And at the same time, madmen rule countries, conquer empires, and slaughter thousands at a whim, only to die of a disease at a ripe old age. In the end, after death, is when Christianity really kicks in. What you did on earth determines what you deserve. Religious artifacts, if you believe in them, merely exist to demonstrate God's power and reaffirm faith in your religion.