I know that in Washington and Louisiana, you can show your driver's license (maybe passport in your case) and they will remove the sales tax from the price at the register. I don't know if it is possible after the fact.
Hey, just look at it as supporting the Nevada public education system!
Edit:
"REFUND OF SALES TAX
TO OUT-OF-STATE RESIDENTS
Sales tax is levied at the time tangible personal property
is sold and delivery taken in the State of Nevada. There
are no statutory provisions for the refund of Nevada
sales tax based upon the fact that tangible personal
property is purchased by a person who is not a resident
of Nevada or a citizen of the United States of America."
Sorry, bro. Nevada is not so accomodating!
Come to Montana, no sales tax!!!