Two dozen crows circling above Santa Rita Avenue on Tuesday afternoon suddenly appeared like a spooky omen of Halloween to come. The scene was reminiscent of the Hitchcock classic, "The Birds."

But at this time of year, the creatures fit in with the landscape: masses of cobwebs draped over stone walls and entryways; tombstones popping up from the earth; and spiders and ghouls lurking about. And on Halloween night, this Old Palo Alto neighborhood will come alive with hundreds of costumed people, flickering pumpkins and a host of cackling witches and moaning zombies.

A green-faced, life-sized witch already flies over Nils Thorjussen's home, and his house has a yardful of tombstones, bats, assorted ghouls and ghostly decorations. He's only halfway through putting together his setup, which will include a smoke machine to enshroud the front yard, he said.

Santa Rita, Waverley and many other streets in Old Palo Alto attract masses of people each year due to its carnival-like atmosphere. Each year Google co-founder Larry Page and Laurene Powell Jobs, widow of Apple co-founder Steve Jobs, put on spectacles for the holiday of horror: pumpkin heads on pikes; a pumpkin tower; a gigantic, hairy red tarantula; anthropomorphic trees (actors on stilts who address trick-or-treaters); and people in ghoulish costumes who jump out in the night.

The theatrical tradition has spread throughout the neighborhood.

"There is a dynamic, in a positive way, of keeping up with the Joneses. It gets a little competitive. It's like, 'Oh -- I need to upgrade,'" Thorjussen said.

Around the corner on Cowper Street, Margaret Chai Maloney's family has set up a frontyard graveyard. Some tombstones bear epitaphs of still-haunting crises: "R.I.P. Enron" and "R.I.P. Freddy Mac."

Each Halloween Maloney's children get extra pumpkins to carve and the family roasts the scooped pumpkin seeds. They'll use some of the pumpkins to make soup -- a special family recipe, she said.

But her favorite tradition involves City Councilwoman Karen Holman, who arrives to make handmade caramel apples with Maloney's children. The confections are distributed to visiting neighborhood kids, Maloney said.

"This neighborhood has a number of young families, and older families are focused on having a safe neighborhood for the kids," she said.

Maloney affectionately dubs one Lowell Avenue resident, Catherine Debs, "Mrs. Halloween." Debs goes all out with 12-foot inflatable ghosts that glow in different colors and other elaborate decorations.

"Catherine is magical. Last year she had a candy store. Every year she puts so much into creating a Willy Wonka-like atmosphere," Maloney said.

At Debs' home, a gigantic inflated black cat with a Cheshire grin nods from the first-story roof. Nearby, the Grim Reaper drives a pumpkin stagecoach. A former San Francisco assistant chief of protocol, Debs knows how to throw a party. This year she'll bring in a hot dog vendor along with distributing a tubful of candy, she said.

Some residents want to revel in a holiday they missed as children. Bryant Street resident David Brunicardi said he has always loved Halloween. But growing up, his parents weren't into the celebration. Now his 6-year-old son is making his own decorations.

"It's being passed on to the next generation," he said, fingering the Popsicle-stick spider his son made, which hangs near the door.

Brunicardi has created his own animated ghost, "Josephine," who stands on the balcony waving a lit candelabra, he said.

He won't reveal the surprise setup he plans for the driveway, but he hints at past efforts.

"Last year, two guys on a scooter got caught in a very big spider web," he said.

For all of the treats people give out -- some have distributed as many as 2,000 pieces of candy -- the real fun is the camaraderie and sense of belonging, Thorjussen said.

"It's like a colossal block party. There's lots of socializing. People have mini block parties on their front lawns. It's a wonderful atmosphere," he said.

Still, Thorjussen hopes his neighborhood's Halloween won't turn into too much of a good thing. If it gets out of control, he's afraid neighbors won't want to do it anymore.

Already, busloads of Halloween "tourists" crowd the streets. It's like Christmas Tree Lane but with kids in the road, he added.

This year, Santa Rita and Waverley are expected to be closed to traffic. Some residents said they hope that fact won't make the neighborhood more attractive. But Thorjussen thinks it'll improve safety.

Obtaining permits to close the streets will require hiring a traffic-management contractor and paying for signage and other barriers. He said he wishes the city would recognize the traffic situation and post an officer unprompted, he said.

"I don't get the feeling they fully appreciate how crazy it gets here. I'd love for the city to step it up. Halloween is the biggest public holiday in Palo Alto," he said.