Teen Titans 15 (May/June 1968) has some clever moments, but overall the story, by Haney, Lee Elias and Cardy, just falls sort of flat for me.
Runaways are at the core of this tale, and a friendly group of hippies who take them in and shelter them, but also provide a connection for them to reach their parents if they choose. Since the nastier elements of the city are preying on the runaway kids, Kid Flash, Robin, Aqualad and Wonder Girl go undercover as hippies.
As I wrote that, I realized why this story doesn't work for me. There are a number of Teen Titans forays into the concept of runaways, the best of which is from New Teen Titans. This tale, with friendly hippies and a singing narrator, is so clean and safe. Even the villain, Captain Rumble, is so cartoony that there is no sincere feeling of threat to these kids.
And it's certainly not a bad story. The art remains inventive and engaging.
And one has to love that it is the singing narrator himself who takes down Captain Rumble with his guitar. The story has to be viewed as a mirror of the hippie era, though, not as a serious work about the issues of runaways.