A group photo will be taken at the intersection of Market, Castro and 17th streets at 5 p.m. Thursday, under the neighborhood's famous rainbow flag.
The plan after that is to "fan through the city looking for Joe Six-Pack," organizers said.
Anyone is welcome to join, organizer Eve Moran said.
Moran, a 30-year-old Saratoga resident, plans to vote for Democrat Barack Obama. She said she is pleased to see a woman running for vice president but doesn't agree with Palin's stances on issues.
She dressed up as Palin for the first time in early October when the Alaska governor made a fundraising stop in Burlingame. Moran wore an outfit she had bought at a Marshalls store in San Antonio, Texas while shopping with her grandmother.
"I got a little bit of notice from the press," she said of the Burlingame event.
She met her fellow organizers at a Sarah Palin look-alike contest held Oct. 22 at the Brava Theater in San Francisco's Mission District.
"That's where I met all these Sarah Palins and they were such good sports," Moran said.
The group has gained attention since, even posing for a photo shoot at the San Francisco Chronicle the other day, she said.
She encouraged anyone who wants to participate in Thursday's event to start shopping.
"Everybody should just go to Goodwill and grab a red blazer," she said. "Those rimless glasses are everywhere, all over the reading-glasses racks at Longs and Safeway."
The McCain-Palin campaign did not immediately return a call for comment.