The president of South Korea biked to work today. Nearly 30,000 cyclists took to the streets of Taiwan's capital. European cities asked their residents to keep cars parked for the good of the planet.

A European Commission spokeswoman says that some 200 million people from more than 1,650 cities in 37 countries participated in some way in World Carfree Day. (Find out more about what's happening and read reactions here, here and here.)

Don't feel bad if you missed out here in the States, though. Although carfree days have been growing in popularity around the world, the idea hasn't exactly taken off in this country (despite some promising individual and local efforts ). I suppose that's no surprise in a nation that has grown so dependent on the automobile, and where many cities still lack decent public transportation alternatives.

I'm lucky enough nowadays to live in New York City, where driving a car isn't just optional -- it's against the norm. I can bike to work most days, and when I don't feel like pedaling, there's always the bus or a subway line nearby to get me where I'm going. Even when traveling to nearby cities, I can often take the train. (I prefer Amtrak's Acela Express over a plane ride to D.C. any day.)

I haven't given up driving completely, of course. My wife and I still keep our great-on-gas mileage Honda Civic for those destinations where public transportation just won't take you. But cutting back has been a great thing for me ... and for my bank account, especially this past summer.

I don't think even the most ardent advocates of World Carfree Day are expecting everyone to give up their cars completely, especially not in this country. But if we could all find ways to drive a little less, it could really add up -- for our wallets and the planet.

A recent NRDC analysis showed that commuting one less day per week, either by sharing a ride, telecommuting or using transit, could save Americans $236 per year on average. And If each commuter car carried just one more passenger once a week, it would cut the nation's gasoline consumption by more than 50 million gallons weekly.

As this commentary puts it, if nothing else, this summer's soaring gas prices should make everyone re-evaluate the wisdom of "commuting solo in a one-ton machine occupying the space of a small elephant."

But I'd also like to see people driving less because I think it makes for happier people and better communities. A recent report from Transportation Alternatives, the New York-based livable streets advocacy group, found evidence that cities making an effort to dethrone the car can reap a wealth of benefits, from increased property values to higher retail spending.

So you may have missed World Carfree Day, but it's never too late to make an effort to drive less. If we do, then maybe by the time the big day rolls around next year, we'll all feel a little more like celebrating.