Look what my wife found:
"Devil Ball put a call into the USGA on Monday morning asking if the traditional wicker baskets would be in play and it was confirmed they would.
Why wicker baskets instead of traditional flags? Let the Merion Golf Club website explain it ...
"The wicker baskets' origin is a mystery to this day. There was a great deal written in 1912, and for three years thereafter, locally and nationally about this new course in Philadelphia. However, there was no mention of the soon-to-be famous wicker baskets. It could be assumed they were not there. By the summer of 1915, William Flynn, Merion's Superintendent, received patent approval for his wicker basket design. Merion had baskets that fall and from then-to-today. It could be assumed, due to lack of written proof, that Flynn convinced Wilson to use the baskets, and Merion received its "basket notoriety" the next year during the 1916 U.S. Amateur."
So, yeah, no concrete proof of why they are used, but it's a cool tradition that I'm glad the USGA is sticking with for the '13 U.S. Open."
Apparently the winner receives one of the wicker baskets as a memento.