What is the little doll on top of Tomoko's phone?
That guy is apparently from the Wii game Opoona where you play a character called "Opoona" that's short and has a number of facial expressions (and one of them has a ball over their head), though they don't always have such a sour look on their faces.





Some ascii art of Opoona with the Yaruo face that Krazer mentioned: