Hi Larry, It's been awhile...and there are some new free Irish genealogy websites available now. The most outstanding for Kerry searchers is Irishgenealogy.ie wherein 600,000 Kerry births and marriages are available. There you will find John Flahiff and Catharine McKenna as parents of a John, 27 April 1851 and a Mary, 8 July 1849 in Kilnandrane, CP Castlegregory. Because you are looking for a John and spouse Cathrine, you may want to pursue this and see if there aren't more children, rather than the John/Mary and Catherine/Wm Moran combos right now. My own John Flahive and Catharine Lynch are on this website with some of their children. This site also has the City of Dublin B&M available free.
Next, The LDS Family History Center has a grand new program they are bringing on line and have added many Irish B&M as well as other neat things. Go to pilot.familysearch.org or to the regular LDS site and use their search drop down-menu to get to the Pilot. It has a lot of potential and much easier to use than the site I mentioned above.
Lastly, the National Archives of Ireland has the 1911 census fully on line and is expecting to have all of 1901 on the site by mid 2010. If you don't find a John/Catherine in the 1901, you may want to reconsider whether or not the family emigrated.
Good luck and let me know how you make out. Best, Mary