If you like singing karaoke with a whole gang of people, there’s now a special social network for you. San Francisco-based Smule is announcing today that it is adding group video for its Smule Sing!

Smule has launched a number of popular, music-themed mobile apps, including Sing! Karaoke, Guitar, Ocarina, Magic Piano, and I Am T-Pain. Now it's turning its website into a social network that it ...