Science Daily has the latest:

In 2010, van Leeuwen first noticed how a female chimp named Julie repeatedly put a stiff, strawlike blade of grass for no apparent reason in one or both of her ears. She left it there even when she was grooming, playing or resting in Zambia's Chimfunshi Wildlife Orphanage Trust sanctuary. On subsequent visits, van Leeuwen saw that other chimpanzees in her group had started to do the same.
The first chimp to copy Julie was her son, Jack. (It seems Zambian chimps have, like so many black Africans, adopted European names.) The practice then spread to 12 or so members of her group (Kathy, Miracle, Val, and so on). Because it is not in the nature of a chimp to meaninglessly stick a piece of grass in its ear (not in his/her genes), the scientists concluded that the behaviour's source is socially learning—indeed, the very foundation of human sociality. No other ape is better than us at copying, learning from others, and cultural innovation. It is said that a human baby (clearly one of the most useless creatures in the history of mammalian evolution) begins to imitate with in the first hour of his/her life. As the mostly forgotten 19th-century French sociologist Gabriel Tarde wrote in his once-famous book The Laws of Imitation: "What is society? I have answered: Society is imitation..."
Are Humans Next?
  • Grass-In-The-Ear Selfie
  • Are Humans Next?

Sadly, Julie passed away, but her innovation survived her.