Yahoo! thinks that kindness can spread as a virus.

To prove it, the brand launched a special campaign called “You In?” designed to inspire a ripple of kindness around the world.

On its site kindness.yahoo.com (pic.) users can tell about their small and big good deeds, share this information in social networks and services such as Facebook, Twitter and MySpace and add them on an interactive global map as small purple hearts.

It is known that Yahoo! wants to conduct its own acts of kindness inspired by people’s deeds.