11.55am: OK, prepare yourselves, the parade is definitely going to stray into silly territory. Apart from the aforementioned blue-haired goons, we now have people dressed as huge kangaroos with bouncy shoes on. You have been warned...
11.50am: A strange group of blue-haired individuals are jumping around on George Street, presumably as a precursor for the start of the proper parade. They are being followed by lots of cars, and throwing things into the crowd - could this be a homage to the infamous 100m bottle incident?
Libby is starting to get excited now:
11.46am: Sailing gold medallist and closing ceremony flag bearer Malcolm Page said he was looking forward to walking in the parade in his home town, adding that his two nephews had taken the day off school to come and see him.
"One of the highlights for me in these parades is actually seeing all the kids and giving them a high five. Out of the 13 athletes on the sailing team, eight of us came away with some bling. We have been a traditional winner for some time but we have not been in the public limelight and it's great that it has been recognised this time."
But Page told the Herald's James Robertson he won't be around to enjoy sailing's newfound profile.
"I'm hanging up my stinky wet suit boots," he said.
11.42am: Herald photographer Wolter Peeters is getting ready to capture the big event:
And first out of the blocks in the Twitter 100m dash appears to be Libby Trickett, who is documenting almost every step of her day:
Totally almost knocked over the Governor!! Yikes. — Libby Trickett (@libby_trickett) August 20, 2012
11.40am: The Sydney parade is the first of a number that will be held around the country. Melbourne is next on Wednesday, then Adelaide on Thursday, Brisbane on Friday, Hobart on Saturday, Perth the following Monday and the final parade will be in Canberra on Tuesday next week.
Silver and bronze medallist, swimmer James Magnussen, said despite not winning gold he hoped his achievements had meant a lot to his fans.
"It will be good to get out there today and say thank you to those who supported me. I set myself some high goals and fell slightly short, but one of the things I'm proudest of is the way I handled those disappointments. While the media might have given me a bit of a hammering it's important to know the people that matter are still behind me."
Magnussen said his family and friends were in his home town of Port Macquarie but he was looking forward to mingling with his Sydney fans during the parade. "If I can see some fans and put some smiles on faces that will make my day," he said.
11.35am: Unencumbered by the distractions of competition, our athletes are letting loose on Twitter during the parade. Here are some early thoughts:
11.30am: Welcome to our live coverage of the first welcome home parade for our London 2012 Olympians. NSW governor Marie Bashir has just delivered the official welcome address to the green-and-gold-clad athletes thronging around the Overseas Passenger Terminal in The Rocks, where the parade is set to commence at midday.
Several roads in Sydney's CBD have been closed to make way for the parade of Olympians - which include gold-medal winners Sally Pearson, Tom Slingsby and kayakers David Smith, Jacob Clear, Tate Smith and Murray Stewart.
It will start at the Overseas Passenger Terminal in The Rocks at 12pm and continue along George Street before finishing up at Sydney Town Hall about 1.30pm.
View Olympic welcome parade in a larger map
The athletes will be greeted by NSW Premier Barry O'Farrell and the Lord Mayor of Sydney Clover Moore at Town Hall, while dancers and drummers will line the street to herald in 2016 host Brazil, the NSW Government said.
George Street will be closed between Goulburn Street and Hickson Road from 10am. Parts of Alfred, Barrack, Bond, Essex, Hunter, Bridge, King, Park, Market and Margaret streets will also be shut. All streets are expected to re-open by 3pm. Further details on the road closures are available on the NSW Transport Roads & Maritime Services website.
Special event clearways
There will be special event clearways for various CBD roads between 8am to 3pm. The NSW Transport Management Centre advised motorists parking in the city to look for clearway signs as vehicles parked in these areas will be towed away.
From 10am to 3pm, buses that travel along George Street will be diverted to Elizabeth Street. Some buses that usually stop at Railway Square will terminate at the Queen Victoria Building instead.
Passengers with bus tickets can use them to travel on City Circle train stations - Central, Town Hall, Wynyard, Circular Quay, St James and Museum - as well as Martin Place train station.
Further details are available on the 131500 transport website.
Accessible viewing areas for spectators with special needs will be set up along George Street outside Wynyard Station and at Martin Place. Two accessible viewing areas will also be opened in front of Sydney Town Hall from 11.15am for those wanting to watch the official ceremony. View the map of the areas via the Physical Disability Council of NSW website.