Above is exclusive video Radaronline.com acquired Friday, showing the then secret location of the wedding.
UPDATE 7:25ET: Jerry O'Connell and Rebecca Romijn just arrived.
The actor, wearing a suit, was photographed pumping gas in his car on the way to the wedding!
UPDATE 7:15ET: Mario Lopez just got onto a black shuttle bus and is being driven to the estate.
UPDATE 6:30ET: Radar has learned the secret location guests were told to meet pre-wedding is the Malibu City Hall, and they're being driven to the nearby estate.
In addition to 20 security agents guarding the estate, one of those agents revealed exclusively to Radar that a helicopter making routine sweeps of the property is, surprisingly, not being used by photographers, but instead, wedding security.
Fergie and Josh are apparently not taking any risks when it comes to uninvited guests crashing their wedding!
Fergie has been on-site since 9am getting hair, make-up, dressed and ready to say "I-do."
UPDATE 5:45ET: Fergie might need to wear a windproof wedding veil later this afternoon when she steps up to the altar!
Though sunny and mild in Malibu today, Radar's team of reporters are estimating 40 mph gusts howling across the area, which could possibly threaten what would hopefully be a perfect outdoor ceremony.
UPDATE 5:00ET: There are now dozens of security agents combing the site where Fergie will be married later this afternoon.
Guests have not yet begun to arrive, but reporters for Radar say wedding staff - all of whom have signed privacy agreements - are being searched and wanded with metal detectors before being shuttled from a secret location and onto the estate.
UPDATE 4:15ET: Security is tight at the secret location - many agents are dressed in camouflage and walking the perimeter of the estate with German Shepherds.
Black canvas is blocking the view from the street and Radar reporters covering the event are describing the site as a "heavily guarded prison."
The wedding is so secret that guests will be shuttled to the site one hour before.
Wedding preparations are underway for Fergie and Josh Duhamel, and RadarOnline has learned exclusively that the glowing bride-to-be and a friend arrived onsite in a Cadillac Escalade at 9 a.m.
Her family and bridesmaids arrived shortly thereafter. "Fergie's party began arriving hours before the wedding to get their hair and make-up done," a source revealed.
Caterers and florists were scrambling around the estate at the crack of dawn, sources say.
"They're putting together the final touches and making sure everything is perfect when Josh and Fergie walk down the aisle later this afternoon."
Stay tuned to Radar for up-to-the-minute coverage throughout the day.