NameBase.org offers a best-guess checker for last names. Users input a best guess at the spelling of a name and the program returns recognized surnames that it thinks are similar. However, this is a very rough-and-ready match, and it features names used in Western countries almost exclusively.
The best way to check the spelling of a live person's name is to ask the person how it is spelled, as many families use variant spellings depending on the part of the country in which they live. For genealogical or historical research, a system known as soundex is used by many records agencies that allows researchers to search for all last names that sound similar to avoid missing records because of spelling variations.