US pop singers Lady Gaga and Justin Timberlake are among the musicians who are giving up social networking websites for a charity campaign organised by co-artist Alicia Keys.

Keys has asked the artistes to stop using Facebook and Twitter from Tuesday - 30 November, World Aids Day until her "Keep A Child Alive" charity campaign raises $1m.

The campaign called the Digital Life Sacrifice will see Lady Gaga temporarily sever ties with her seven million Twitter followers.

For the campaign, celebrities have filmed "last tweet and testament" videos and will appear in ads showing them lying in coffins to represent what the campaign calls their digital deaths.

Keys said all the artistes she had approached had accepted her request to sign up. "Once I got people on the phone and I was able to paint the concept for them, everybody was in," she said.

The celebrities will go back to social networking sites once they reach their target from the campaign.