Davina McCall, Matt Lucas and Chris Evans were among celebrities launching this year's Red Nose Day for Comic Relief in London.
Celebrities launched the latest Red Nose Day in London
They announced the 11 March telethon, revealing that this year's theme was "big hair and beyond".
It will include a new Celebrity Fame Academy contest, a fundraising Little Britain DVD and a charity single by pop group McFly.
It is the 20th anniversary of Comic Relief, which has raised £337m so far.
It aims to tackle poverty and social injustice, with 40% of the money raised through Red Nose Day allocated to work in the UK and 60% to Africa.
Singers Sir Elton John, George Michael and Robbie Williams are among guest stars featuring in Little Britain sketches to be broadcast during the seven-hour telethon then sold as a charity DVD.
The BBC One show will also include appearances by comedians Peter Kay, Dawn French, Ricky Gervais, Lenny Henry, Ruby Wax and Liza Tarbuck.
Comic Relief Does Celebrity Fame Academy will return for a second series in late February, culminating in the finale on 11 March.
Singer Robbie Williams has a Little Britain cameo role
The previous charity Fame Academy was won by actor Will Mellor in March 2003.
Radio 1 disc jockey Chris Moyles and his team will spend a week travelling from John O'Groats to Lands End in the run-up to Red Nose Day, collecting donations along the way.
McFly will release their double A-side Comic Relief single All About You/You've Got a Friend on 7 March.
Viewers take part
This year's theme will encourage people to change the way they look for the day in addition to raising money.
For the first time, Comic Relief is taking viewers to Africa to see how their donations on previous Red Nose Days have helped transform people's lives.
Big Brother presenter Davina McCall will take three Coventry Bus Drivers to Kenya and Lenny Henry will take a family from Bristol to Ethiopia.
The previous Red Nose Day raised more than £35m on 14 March 2003, the highest figure raised on the day of the event.