The young generation of the 1960s demonstrated its complete rejection of the values of their parents in many ways. They protested for civil rights and against the U.S. government's involvement in the Vietnam War. They openly experimented with psychedelic drugs and the new sexual concepts of free love. But mostly, they grew their hair long.
Very, very long.
Commonly referred to as hippies, this group of mostly young people expressed their counter-culture values in a variety of ways and through numerous mediums. These included, but were not limited to, psychedelic rock music, pop-art slogans like "tune in, turn on, and drop out," and acts of civil disobedience, ranging from sit-ins and demonstrations to handing out flowers to police officers.
The hippie movement likely reached its apex in 1967 with the so-called "Summer Of Love" in San Francisco. Not long after that, that cities one-time hippie mecca of Haight-Ashbury degenerated due to rising crime and a lot of bad drugs. Many of the original hippies subsequently took to the country to start their own communes.
Today, the hippie movement is smaller but still very much alive through music-based communities like the Dead-Heads, and latter-day bands like Phish. There is also a thriving hippie presence in the blogosphere at sites like Hippy.com and Hip Planet.