Comic Relief's 10th Red Nose Day is on course to beat its own fundraising record set two years ago with more than £37m donated so far.
Celebrities at the launch of this year's Comic Relief appeal
By 0200 GMT, viewers watching the BBC One comedy fundraising marathon had pledged £37,809,564 for good causes in the UK and Africa.
Organisers are hoping to beat the 2003 total of £61m.
Comic Relief, held every two years, was launched 20 years ago with a live BBC broadcast from a refugee camp in Sudan.
Since then, it has raised well over £300m for some of the poorest and most vulnerable in Africa and the UK.
Cast of thousands
More than 2,000 comedians and celebrities have been involved since the beginning.
This year, in addition to the sale of Red Noses, more than £1m has already been raised from sales of a Little Britain DVD.
A further £1m has been raised from phone votes to Fame Academy, which reached its climax on Friday evening, when viewers voted BBC Radio 1's Edith Bowman the winner.
She beat EastEnders actress Kim Medcalf into second place after delivering a rousing rendition of Oasis's Champagne Supernova as her final number.
Earlier, Stephen Fry made a guest appearance on BBC Radio 4 soap The Archers.
Station listeners chose the comedian to feature in a special episode penned by Victoria Wood.
Fry beat Ewan McGregor, Sir Ian McKellen and Liza Tarbuck for a part in Victoria Goes to Ambridge.
It will be repeated at the end of Home Truths on Saturday. The stunt has raised £13,448 for the appeal.
Fry, who also took part in a University Challenge-style quiz with actor Hugh Grant, said: "Lordy, Lordy, I couldn't be more thrilled. I'm more nervous than I've probably ever been about anything else."
Victoria Wood with Buffy Davis, who plays Jolene Perks in The Archers
Other Comic Relief highlights included Sir Elton John and singer Robbie Williams making a cameo appearance in a special edition of Little Britain.
Comedian Rowan Atkinson took to the rooftops of London landmarks with singer Rachel Stevens.
Radio 1 DJ Chris Moyles and his team have so far raised £583,278 during a week-long road trip from John O'Groats to Lands End.
Elsewhere, The Charity Commission has warned of bogus collectors saying they are raising funds for Comic Relief trying to operate in supermarkets.
Safeway's staff in Worcestershire were contacted by fraudsters who said they wanted to raise money for the appeal.
But they discovered the charity name was fake and its Comic Relief registration number did not exist.