“Mormonism and Science/Global or Local Flood” is a useful page provided by FAIRLDS.org that might help some of you better grapple with some of the issues around Noah’s Flood. I also have a few things to say on my LDSFAQ page about science and religion.
Update: A thoughtful piece on the challenges of understanding the scriptural accounts of the Flood comes from a BYU professor, Duane E. Jeffery, in “Noah’s Flood: Modern Scholarship and Mormon Traditions,” Sunstone, Oct. 2004, pp. 27-45. The link is to a 3-MB PDF file for the whole Sunstone issue, in which the article on Noah’s Flood begins on page 29.