Misinterpretation of the term "tar balls" which are literally balls of tar. These are found along the coast of Hawaii. Jack Johnson is a surfer (from Hawaii)turned musician, hence the reference to a common item that you'd see when surfing.
by C. Eric C. July 07, 2006
by JayFnG July 07, 2006
by BamaBoyy March 31, 2005