The term "love-in" was one of many co-optings of Timothy Leary's famous mantra "Tune in, turn on, drop out", which gave rise to the original San Francisco "be-in" gatherings of 1967, a pun on the word "being". Another example is a "sit-in" protest, or John Lennon and Yoko Ono's public "lie-ins" from their hotel beds.
Despite its British leading man, this film was never released in the UK.