I think the only "famous" people I'm related to might be horse thieves. I'm talking about the kind of DNA test that is offered at ancestry.com.
AncestryDNATM includes:

  • Full breakdown of genetic ethnicity
  • Dynamic list of potential new relatives updated in real-time
  • Simple process to receive your personal results online within weeks
  • Ability to integrate with Ancestry.com
  • Test is for both men and women
Here's the faq they have online with more details AncestryDNA Frequently Asked Questions

I was born to be a pessimist. My blood type is B Negative.