Hyperdimension Neptunia Mk-2 has a take on social networking through the mintsubu system. Similar to Twitter, avatars chat and occasionally link players to event scenes.
Many of the avatars are video game parodies. See if you can spot "Sneak-san", Hunter-san, and Maryo standing next to characters like Nepgear, NIS, and Gust.
Planeptune
Lastation
Lowee
Leanbox