Leland Meitzler in his Genealogy Blog has consolidated for us a list of all the Family Search databases that deal with United States birth and christening records. There are 47 different databases covering 34 states.
You can see the list at FamilySearch.org, of course, but it may be helpful to see then in one consolidated list. Each of the listed databases are hot linked to the real deal at the Family Search website. Check it out at http://www.genealogyblog.com/?p=10923