A stamp to celebrate Team GB's gold in the rowing men's four will be will be on sale by lunchtime tomorrow.
The honour will be the first time Royal Mail has issued stamps on a Sunday.
Royal Mail will produce the stamp - celebrating Alex Gregory, Pete Reed, Tom James and Andrew Triggs Hodge's success - within 24 hours.
A fleet of 90 Royal Mail vehicles will deliver the stamps to more than 400 post offices by lunchtime tomorrow.
This is the ninth gold medal stamp to be issued by Royal Mail.
The parents of gold medal winning Team GB rower Katherine Copeland always believed their daughter would achieve Olympic glory.
Her mother and father Penny and Derek and brother Finlay were all at Eton Dorney to cheer her on today.
We had faith in her, we thought she could do it.
I think the lightweight women have been completely overlooked. No one has been following them. They all talk about other boats, but not so much the lightweight women.
But it is not a surprise to us.
She is so determined. She decides what she wants to do and she makes it happen. Nothing is going to stand in her way.
Pete Reed won Gold in this morning's men's coxless fours rowing:
Feet haven't touched the ground yet. Tweets and photos will come flooding in. Firstly, thank you for our support. You know who you are. Pete
Super Saturday got off to a sensational start as Britain's rowers claimed two golds and a silver.Read the full story ›
Katherine Copeland and Sophie Hosking moments after their gold medal win and below Alex Gregory, Tom James, Pete Reed and Andrew Triggs Hodge with their gold medals.
Mark Hunter said: "We gave everything, we tried everything, we wanted to win so badly, sorry to everyone we've let down."
Zac Purchase: "I just wish we'd been a little bit quicker for everybody here."
Great Britain's Zac Purchase and Mark Hunter have won the silver medal in the restarted men's lightweight double sculls, missing out in the closing moments to Mads Rasmussen and Rasmus Quist of Denmark who took the gold.
Great Britain's Purchase and Hunter will be allowed to compete in the restarted men's lightweight double sculls once a faulty seat clip if fixed, according to BBC Sport presenter Matthew Pinsent.
The race is due to begin again at 12:21.
The men's lightweight double sculls race stopped and will be restarted because of a broken seat in the Great Britain boat.
More to follow.
Speaking to BBC Sport, Gold medal-winning rowers Kat Copeland and Sophie Hosking were still to fully take in the scale of their achievements:
Kat Copeland: "I can't believe this is real, that we just won. We just won the Olympics! We're going to be on a stamp tomorrow! I've been trying all week not to think about it because it made me cry. I know this isn't the Oscars, but can I thank my mum and dad?"
Sophie Hosking: "It's something that we've been working on for so long, and there are so many people to thank. I just can't believe it's happened."