Ancestries of "famous", "infamous", or "notable" persons are already done by numerous reputable researchers. One of the more prolific are the articles and books by Gary Boyd Roberts. Search Amazon, or your local library, by his name and see some of his works.
Ancestors of American Presidents (revised periodically)
Notable Ancestors (multi-volume set)
"The Royal Descents of 500 Immigrants to the American Colonies", Gary Boyd Roberts (revised periodically)
He has done (I'm not sure if book form or an article), cousin relationships of various "famous" Americans to Princess Diana.
There is also "Planatgenet Ancestry of Seventeenth Century Colonists" by David Farris
I think some others have done tie-ins of "famous" people to various Mayflower passengers, as well.
To do your own tie-in to these people (famous, royal, Mayflower, whatever), you need to have developed your own ancestry in good form back (usually) to the immigrant - because you are generally looking for a tie-in of a person in your ahnentafel to someone else's ahnentafel.
Until the present time, the numerical preponderance of tie-ins to these people has required New England ancestry, becase they have the most descendants of American immigrants and are, as a whole, the best documented lines. However, as each generation passes, more and more Americans from other places are becoming more and more related to millions of Americans; and more and more Americans are receiving some part of their ancestry from New England. And our American intermixing is thus becoming more and more intertwined.
Contrast American relationships to, say, Sweden; where an ethnic Swede knows they are related to every other ethnic Swede who has, is, or will have ever lived. Americans often have trouble going back to 1620, then with only part of their ahnentafel, and before that is usually limited to a limited number of ancestral lines.
For an example of how I have tied various of my New England lines (I only have about 100-150 New England immgrant ancestors that I have identified.) to "famous" or "notable" people, see here:http://freepages.genealogy.rootsweb.ancestry.com/~riss/baldw...
These web pages don't have my sources. If anyone is actually interested in the details of the sources I consulted for these pages, see here:http://wc.rootsweb.ancestry.com/cgi-bin/igm.cgi?db=taylor-ba...