SAN CARLOS — Underneath the trees at City Hall, people clamored for the freebies Yahoo! was giving away Monday morning.

No, it wasn't computers or software or even technologically focused. The Internet giant was handing out free compact fluorescent light bulbs to residents in celebration of San Carlos being ranked third in Yahoo's "Be a Better Planet" nationwide campaign.

Omar Ahmad was among the crowd who grabbed from a pile of 500, 60-watt bulbs delivered by Yahoo's bio-diesel "Green Guzzler" shuttle bus. Another 4,500 more bulbs will be delivered to the city over the next two weeks.

Ahmad left with a light bulb for good measure, even though he has already switched out all of his bulbs for the environmentally-friendly kind during an "energy makeover."

"Hey, I saved money," said Ahmad, who estimated the switchover gave him a 20 percent reduction in energy costs. "And it's nice to do something to save the environment."

On May 14, Sunnyvale-based Yahoo! and Global Green USA kicked off "Be a Better Planet" in New York City's Time Square. The Web site issued a challenge to find the greenest city in America.

Over the next several weeks, people pledged to fight climate change.

They were asked to alter their habits by air-drying their clothes in the spring and summer; driving the speed limit; carpooling or taking public transit, or installing solar panels to power the water heater.

What people were able to pledge equaled green credits for their city and free light bulbs for themselves.

It was Hastings, Neb., that got the top billing of "green" city. Mill Valley placed fourth and Walnut Creek was named No. 9. First prize was either $250,000 dedicated toward city greening projects, or a fleet of hybrid taxicabs. Hastings chose the money.

If 5,000 environmentally-sensitive bulbs were installed in San Carlos, that's equivalent to taking 150 cars off the road for one year or removing 30,000 to 140,000 pounds of carbon dioxide from the atmosphere, according to Ann Iverson, of San Carlos Green.

The group works with the city and plans to provide programs revolving around energy and water conservation, sustainable gardening and landscaping, and recycling.

So far, the city of San Carlos has installed solar panels at its corporation yard, waived permit fees for solar panel installation at residences. Also, by the end of the year, all traffic signals will have LED lights, which have low power consumption.

"You can't say one small action doesn't matter," Iverson said. "I believe we've reached a tipping point. People need a little reminder and to take action."

She said people rallied for San Carlos to be in Yahoo's top 10. Just two days before the June 8 deadline for pledges, Iverson learned that San Carlos was in ninth position. She immediately started spreading the word about the campaign.

The city deserves the bragging rights, said Nicki Dugan, spokeswoman for Yahoo.

"There was a very impressive number of San Carlos residents who pledged," she said.

Dugan added that Yahoo was "blown away" at the crisis at hand after viewing former Vice President Al Gore's film, "An Inconvenient Truth."

"We're really focusing on getting the community into action," she said.

San Carlos Mayor Tom Davids said he is pleased that San Carlos was honored by Yahoo! and that residents worked so hard to get the city on the list.

"We're reinforcing that we are the 'city of good living,'" he said.

Residents can stop by the San Carlos City Hall at 600 Elm St. to get a light bulb. San Carlos Green also will be distributing them at its booth during Hot Harvest Nights on July 5 and July 28.

On the Web: http://www.sancarlosgreen.org

Staff writer Christine Morente covers faith, families and North County. She can be reached at (650) 348-4333 or at cmorente@sanmateocountytimes.com.