It isn’t often that the nonprofit world becomes a hot topic on Twitter.

But today’s Mashable Social Good Conference has become a major hit on the popular social-networking Web site.

The hashtag #socialgood — which is used to mark all Twitter updates associated with the event — has been one of the 10 most popular phrases on Twitter for much of Friday morning.

The audience at the event — which is taking place at the 92nd St. Y in New York — is packed with people on laptops.

When a speaker pauses during a presentation, the sound of dozens of clacking keyboards is usually the only audible sound.