Like Help-Portrait, many ideas start simply, then strike a chord with audiences online and spread quickly. So it was with yesterday’s Generosity Day.

On Friday, Sasha Dichter (@sashadichter), who is the Director of Business Development at Acumen Fund, a global non-profit venture fund that invests in enterprises that fight poverty in the developing world, posted a blog entry that challenged people to turn Valentine’s Day into an opportunity for greater good.

Inspired by a talk at last week’s Social Media Week New York, the idea was to “reboot” Valentine’s Day as “Generosity Day: one day of sharing love with everyone, of being generous to everyone,” he wrote. “Let’s make the day about love, action and human connection – because we can do better than smarmy greeting cards, overpriced roses, and stressed-out couples trying to create romantic meals on the fly.”

The goal was to spend the day saying “yes” to everything that was asked of you – all day long, leading to big and small acts of generosity. Those who participated were encouraged to share their experiences by tweeting and using the hashtag #generosityday.

More than 3,000 people tweeted and bloggers and national media picked up on the story.

And for good reason. We’re all in favor of ways to encourage giving back – in big and small ways – and look forward to Generosity Day becoming a yearly tradition. Who’s with us?

You can join www.facebook.com/generosityday for updates.