By Stephanie Holmes
BBC News, Rome
Ripples of spontaneous applause, whistles and shouts of encouragement have echoed across St Peter's Square as the thousands of pilgrims gathered to pray for Pope John Paul II make their presence felt.
The mood has picked up since the morning
In the piazza, the atmosphere has been transformed and there is almost a sense of celebration.
Inside the vast basilica, the heart of the Catholic Church, a mass is being held.
Outside, people are speaking of everything that Pope John Paul has achieved in his papacy of nearly 27 years.
Young Italians wearing yellow bandanas carried a barrier reading: "You called us and so we are here" as they made their way towards the piazza.
The arrival of so many young people has sparked a shift in mood as the mumbled, tense prayers of the morning are replaced by enthusiastic chanting of the Pope's name.
They call "Gio-van-ni Pau-lo! Gio-van-ni Pau-lo" in unison towards the window where he drifts in and out of consciousness, almost as though the sound of their voices will give him strength.
"He has been very close to us children," said eight-year-old Federica Corti, as her fingers fiddled with a string of rosary beads.
"He always said that whenever he was with children, he too would feel young," she said.
Thirty-three-year-old Simone Luciani said the Pope, known to Italians as Papa Giovanni, had taken a new approach to spreading faith.
"He spoke directly to young people. The future of the Church is with us and he made a whole generation much closer to the Church," Simone said.
Papal spokesman Joaquin Navarro-Valls said on Saturday morning that the Pope had tried to speak a few words in the early hours of the day, and had been made aware of the thousands of young people who had gathered to pray for him.
"In fact, he seemed to be referring to them when... he seemed to have said the following sentence: 'I have looked for you. Now you have come to me. And I thank you'," the spokesman said.
As if responding to this message, throughout the afternoon hundreds have surged onto the square, mothers pushing young children in prams, elderly couples holding hands and huddles of nuns glad to be present at this moment.
The pilgrims now stand facing the papal apartments, looking upwards towards the window where Pope John Paul appeared so many times to address believers.
"He is my next-door neighbour," said 60-year-old Giuseppe Parti, who lives near the Vatican.
"I'm not a particularly religious man, but I feel geographically, physically and spiritually close to him."
His daughter agreed.
"Pope John Paul II shortened the distances between the Church as an institution and its public. He had a spontaneity to his character that isn't often seen in the Church," 29-year-old Viviana said.
The roads leading to the Vatican have been cordoned off, police cars block the paths of vehicles and dark-clothed security agents guard the few remaining entrances to St Peter's Square.
Some pilgrims watch their mobile phones for news, others hold portable radios to their ears.
Television crews, kept out of the piazza, point their cameras towards the basilica.
About half a mile away, at the end of the broad avenue leading towards the Vatican, a sea of satellite dishes are in place, as presenters broadcast the latest news around the world.
As she walked slowly to join those beneath the papal apartments, Sister Eva Hermana, an Argentine nun, said the number of people in the piazza demonstrated the love that people feel towards the Pope.
"There are many here, but across different languages, different countries and different cultures, we are all joined together in thinking of him. He has united us all in this way," she said.
A young couple, Emanuela Tinca and Emanuele Imondi, both Italian students, said they had come to be close to a pope who had made great efforts to draw young people towards the Catholic Church.
"We love him and we came here because we wanted to pray for him. He was always so focused on youth. On Sundays the crowd was always crammed with young people," Emanuele Imondi said.