KEY POINTS:
Sydney Catholic Cardinal George Pell will officially launch World Youth Day at a harbourside Mass this afternoon, following a day that gave Sydneysiders a taste of what the next six days will bring.
Thousands of pilgrims greeted the 3.8m high, 40kg WYD cross as it arrived by ferry at Circular Quay after a 70,000km journey around Australia and began its trip across Sydney.
The cross - which organisers describe as the Olympic torch of WYD - was thronged by cheering and chanting pilgrims who followed its progress along central business district streets closed for the procession.
Larger crowds of up to 500,000 are predicted for the arrival by boat of Pope Benedict XVI on Thursday, and for the closing Mass at Randwick racecourse on Sunday.
With 300 road closures, 500 special event clearways and the closing of the Harbour Bridge on Saturday, Sydney is bracing for chaos.
Even with 34,000 extra bus and 4000 extra train services planned for the week, New South Wales Transport Minister John Watkins has warned that downtown Sydney will not be able to cope unless one-third of its commuters leave their cars at home.
As Sydney airport yesterday groaned under the pressure of up to 8000 extra arrivals - equivalent to 16 jumbo jet-loads - the Immigration Department confirmed that the event is likely to be Australia's biggest-ever drawcard.
It said thousands of pilgrims had already flooded through Australia's major airports, and airlines had reported that all flights were full, with extra flights and charters being organised.
"Numbers arriving for WYD will more than double the 40,000 who travelled to Melbourne for the 2006 Commonwealth Games, and rival the record 110,000 foreign tourists who attended the Sydney Olympics in 2000," a department spokesman said.
Not everyone is happy.
Critics have attacked A$160 million ($203.5 million) in federal and state government funding, the disruption to the city, and disappointing hotel bookings - despite forecasts by the NSW Chamber of Commerce of a A$230 million injection for the state economy.
Pope Benedict is also under pressure to deliver a stronger apology to victims of sexual abuse than he did in the United States, which he indicated would the model for an Australian apology.
Yesterday prominent Jesuit priest Father Frank Brennan joined the victims' support group Broken Rites and individual victims of abuse by priests in calling for a tougher line.
"I think it highlights two things," Brennan said of the Pope's promised apology.
"One is that when church leaders themselves make mistakes, they should apologise," he told ABC radio.
"The second is that it highlights that there has to be a very firm commitment to proper processes, and what were looking at here are issues not just to do with sexual abuse, but with the transparent exercise of power."
WYD co-ordinator Bishop Anthony Fisher said Australian Catholics welcomed Pope Benedict's compassion and leadership on the issue, and would continue doing all it could to bring healing to victims of sexual abuse.
"Given our efforts to do the right thing in this very difficult area, we're heartened by the Holy Father's words and we look forward to hearing what he has to say," he said.
Meanwhile, internet networking site MySpace has claimed that WYD was failing to connect with the youth of Australia.
MySpace said a poll of users aged between 14 and 24 years had found 77 per cent believed the church was out of touch with youth, 53 per cent felt they could not become involved with WYD because of the church's stance on sexuality, and 89 per cent rejected the notion they should remain virgins until marriage.
The poll also found 61 per cent favoured contraception over abstinence as a means of preventing sexual disease and reducing the risk of unwanted pregnancy.