What happens if you are married in one state, and then when you go to
Vegas on vacation, you get married again (to the same person)?
How does that work legally? 
Are there any impacts at all?

Dear bluesteel101-ga;

Thank you for allowing me an opportunity to answer your interesting question.

A legal marriage in ANY state is recognized as valid in ALL states
(with the exception of some of the homosexual unions that are being
registered in some jurisdictions nowadays). If a man and woman are
currently legally married in one state they are considered legally
married in EVERY state, and a ?remarriage? in any state would only be
considered purely symbolic. This ?renewing of vows?, as it is known,
is a symbolic act that is not legally sanctioned nor does it have any
legal impact or ramifications.

If you somehow managed to wrangle a marriage license in Nevada it
would not be valid if you were already legally married.

On the other hand, if a man and a woman were PREVIOUSLY legally
married but legally DIVORCED, then such a remarriage in Nevada, or
indeed any other jurisdiction, would be considered a legal
solemnization of a matrimonial union for all intents and purposes as
if the couple were never married prior.

I hope you find that my research exceeds your expectations. If you
have any questions about my research please post a clarification
request prior to rating the answer. Otherwise, I welcome your rating
and your final comments and I look forward to working with you again
in the near future. Thank you for bringing your question to us.

Best regards;
Tutuzdad ? Google Answers Researcher

Great answer - thanks a bunch!