Why is there a giant duck outside Cambridge City Hall right now?

A. Cambridge opens its gates to admit the Trojan Duck
B. A giant rubber duck admonishes Cantabrigians to reduce litter to keep local waters clean
C. The city of Cambridge finally recognizes Duck Day as a city holiday

answer after the jump…

The answer is B. Today is the Cambridge Science Festival, and an organization called Think Blue is in fact asking us to help keep local waters clean by reducing litter.  Why the duck?  No soap, radio, I suppose