With just nine days to go until Santa shimmies down those chimneys, letters to the big, jolly guy are coming in fast and furious.
But this year, mixed in with the letters asking for toys and video games are an increasing number of requests for warm coats, food and help paying the electric bill to keep the heat on.
"The common theme this year seems to be a single mom with young kids, the parent has left -- they don't know who the father is, or the father left -- and they can't pay the bills," said Pete Fontana, head of the United States Postal Service Operation Santa in New York.
Want to help a family in need this Christmas? Hundreds of "World News" viewers already have taken action. For more on how you can help, read to the end of this story or CLICK HERE.
It's Fontana's post office in midtown Manhattan -- right across the street from Penn Station -- where most of the letters to Santa arrive each year from around the world. He's expecting about 2 million letters this year.
Post offices in two dozen other locations across the country also accept letters. Most are addressed simply to "Santa Claus, North Pole."
Though many considered last year to be the toughest financially since the economic downturn began, Fontana said, it appears that more people are struggling this year, judging both from the letters and the decreased number of volunteers who sign up to fulfill some of the writers' wishes.
"We had one little girl write in and say all she wants is a winter coat for her mom. Nothing for herself," he said. "We had another letter for grandparents and they wanted to put a turkey with the trimmings for the holiday dinner ... but they couldn't even get their medicine."
Other letters are similarly heartbreaking.
Eight-year-old Skayla told Santa that her mother doesn't have a job and her father lives in the Dominican Republic, leaving it up to her grandmother to buy everything. She asked for clothes and shoes for herself, her 7-year-old sister and their infant brother, even including their sizes.
"Thanks Santa," she wrote," I LOVE YOU."
Ruth, a single mother of three, made a similar request for clothes and shoes "and a bit of toys (IF YOU CAN.)"
"I'm trying to get help as soon as possible," she wrote. "I'm desperate for help. I don't work and I barely have money."
But for Shadybeth, a little girl living with her ill grandmother, a Merry Christmas would mean a permanent place to live.
"Maybe that's why you don't remember me Santa. We still living in another shelter," she wrote. "My grandmother is very sick and we need our place so she could rest."
She ended her letter with a postscript: "Santa Please try to help this time. God Bless you."
Kati, a 13-year-old living in the projects in the Bronx in New York City asked Santa this year for an iPod touch or jewelry.
"Santa, I have been a good girl, I do the right thing even if stuff happen," she wrote. "I love my family and I'm very grateful."
Sad Letters Mix With the Fun, Whimsical Requests
Fontana said his post office has gotten about 700 volunteers this year. Individual volunteers can take up to 10 letters to fulfill. Large companies and corporations have no limit.
Typically, he would have gotten double that number of volunteers by now.
"I think people are being very careful how they spend their money now," he said.
Still, it's not all bad news. The children have penned some creative letters.
"Children will give you a whole list. I had one give me three pages of an Excel file," he said, noting that the child even included the item numbers from the Toys 'R Us catalog for easier shopping. "Fifty items on each page."
"Then you have those that will go through the catalog and cut and paste the items into the letter," he said.
Recently, he got a letter from a 17-year-old in Japan reminding "Santa" that he didn't come when the letter-writer was 12.
"I was sad," the teen wrote. "So please try and visit my home this year. I will wait."
And all those volunteers -- those that can afford to -- are more than willing to go big.
On Friday, a woman picked up a letter from a child that only wanted a piano for Christmas, Fontana said, and she was determined to deliver.
"I said, 'Just one problem, a piano is not mail-able,'" he said. "So we wound up with a Yamaha keyboard."
'World News' Viewers Reach Out
After sharing this story on our broadcast and website, "World News with Diane Sawyer" received an overwhelming flood of e-mails with offers to help. Hundreds of people wrote, asking where they could send gifts to Santa letter authors.
"I was so touched to see the story about how different the letters to Santa are this year," wrote Linda from Middletown, Conn. "I just had my first child last December, and I feel so blessed that I can provide for her without a single thought. ... But so many parents are not as lucky."
Nicole from southern Louisiana wrote with several ideas for things to send.
"I would like to send a JC Penney gift card or a Wal-Mart gift card," she wrote, adding that she thought of purchasing a food voucher for a Christmas meal from a local grocer.
Dustin wrote us, "I'm 19 years old from Oxford, Ohio. ... I want to help as much as I can."
"We would like to help out the little girl who asked for a coat for her mom," wrote Arti. "This little girl isn't even asking for herself, and we want to help her."
Erika, a 25-year-old living in New York, saw our story and wrote, "It takes a moment like this to put the 'big' problems into perspective. ... Thank you for reminding us all what the holidays are really about -- giving, not getting."
And Dana, who's been out of work for two years, said he and his wife, Phyllis, were touched by the letters.
"Christmas will be somewhat light for us this year, yet we are still blessed and would like to share what we do have," he wrote.
How You Can Help
ABC News has responded to each of these letter writers with information on how to help. If you want to help make a Christmas wish come true, the best way is by contacting a local post office participating in Operation Santa.
If there isn't a post office in your area taking part in the program, the U.S. Postal Service asks that you do an internet search in your area for other charities that also answer letters to Santa.