U.S. Treasurer Rosie Rios autographs uncut sheets of currency during an event that allowed shoppers to buy "rare currency, un-circulated coins, medals and limited-edition 2013 collector sets in Washington, Dec. 11, 2013. Tom Williams/CQ Roll Call

WASHINGTON-What's the one Christmas gift we really all want? The one thing we won't return? Not socks that's for sure, but cash.

At the Bureau of Engraving and Printing, tourists and locals lined up Friday to get their cash autographed by the Treasurer of the United States Rosie Rios to give as Christmas gifts. Visitors could even hand in their dirty circulated money for clean uncirculated dollars, including the new $100 bill, truly the Christmas gift everyone wants.

Rios' signature appears on dollar bills and today she personally signed the bills, even autographing them specifically for that special relative.

"It is absolutely the most unique gift you can give somebody for the holiday," Rios said, adding that she signed money today for people from all over the country and the world including China, California, Colorado, Tennessee, Ohio, and many more locales.

"The person people ask me to sign the most to are their in-laws, either their father-in-law or mother-in-law." Rios said. "It's a great way to curry favor with the relatives is what I'm guessing."

Cathy Mehrtens and her family came all the way from Los Gatos, Calif., visiting for one day before spending the holidays with family in Roanoke, Va. She said her son "insisted on visiting the money store."

"You can buy people lots of things, but you can't buy them anything as unique as this," Mehrtens said, noting she will be giving a signed two dollar bill to her niece.

Mehrtens' children Claire and Gavin Frank-Mehrtens were just as excited to meet Rios as to get their bill signed with Claire saying, "It was really cool because I never meet anyone that famous."

So, who will 9 -year-old Claire be giving her signed cash to?

"I'm going to keep it to myself," she said hugging the bills.

Her brother got a $2 bill for his best friend.

"I kind of ran out of ideas, I didn't really know what to get her so I decided this was cool," he said, likely echoing the thoughts of many who lined up today.

Tourists who got their money signed could also go on a tour and see the cash hot off the presses, something Val Wood visiting from Dayton, Ohio, did, saying because she's an accountant she thought "it would be cool to see how money was produced."

Wood is giving her signed bills all to "people in accounting and finance."

Also for sale at the Bureau of Engraving and Printing are uncut currency sheets and a limited edition coin honoring the Girl Scouts, both items Rios also signed.