Checking for duplicate records

If I have an import file that does not have a unique identifier, is there a way to check for duplicates that is pretty bullet-proof?  In other words if an existing record is:

First Name = Bob
Last Name = Jones
Street Address = 123 N 47th Avenue

and the import record is:

First Name = Robert
Last Name = Jones
Street Address = 123 North 47th Avenue

Can we identify the fact that they may be one and the same person?

--Steve