Bosses at the Rock & Roll Hall of Fame in Cleveland, Ohio, have marked John Lennon's 70th birthday by 'burying' a time capsule containing the late Beatle's CDs, books and notes he wrote to his wife Yoko Ono.
Had he lived, Lennon would have turned 70 on Saturday.
The capsule, to be kept in the Cleveland museum's archives, will be opened in 2040 - on Lennon's 100th birthday.
Concerts, art exhibitions and other special events are being held around the world this weekend to mark the singer/songwriter's birthday.
One of the most anticipated events is an outdoor screening of the film Lennon NYC in Central Park, New York City.
Meanwhile, Lennon's widow Yoko Ono is in Iceland, where she will commemorate her late husband's birthday by lighting a peace tower, which will beam lasers into the night sky.
Ono has created a website via YouTube.com where Lennon fans can post their own tributes to the late Beatle.
Announcing the venture in a viral video on Friday, she said, "I hope you'll join me and the family of peace around the world to celebrate this very special day.
"Send in your own video tributes to YouTube and we will share in keeping his memory alive."
Lennon was shot dead outside his New York City home in 1980.