Jonah and the Whale - Is there any scientific proof that it is possible to survive in the belly of whale? The book of Jonah records that Jonah spent three days in the belly of a great fish (possibly a whale).  


  And the LORD appointed a great fish to swallow up Jonah. And Jonah was
  in the belly of the fish three days and three nights.  Jonah 1:17 ESV


Is there any scientific evidence that suggests it is possible for a person to survive in the belly of a whale, or are we left to conclude that this was part of the miracle?
Cecil Adams (aka "The Straight Dope") did a lot to debunk later-day Jonah stories here: http://www.straightdope.com/columns/read/2294/have-any-real-life-jonahs-been-swallowed-by-whales-and-lived

Basically, he says that while many would like to believe this is a phenomenon that has been reproduced, all the stories range from apocryphal to fraudulent. As such, yes, the fact that Jonah was preserved for three days in the belly of the whale, was in fact a miracle. 

Theological Import

The fact that Jesus alludes to the same in Luke 11:32 (the sign of Jonah being given instead of a miracle) may lead one to a discussion of the difference between a sign and a miracle - but in both cases the effect is the same. It is a physical situation in which the natural human response is to see God's direct intervention. I would argue that the point of Luke 11:28 (A wicked and adulterous generation asks for a miracle, but no miracle will be given it except the sign of Jonah) specifically points to the fact that people wanted a magical reproduction. Nowadays, we are not a magical culture, but rather a scientific one. As such, we ask not for a miracle but a scientific explanation.  I suspect Jesus would say of his own resurrection, that no explanation would be given it, except the sign of Jonah.