Well, Catalonia during the Spanish Civil War is the tried and true example, but there are many others. Here are some excerpts from George Orwell's "Homage to Catalonia":

"The Anarchists were still in virtual control of Catalonia and the revolution was still in full swing. To anyone who had been there since the beginning it probably seemed even in December or January that the revolutionary period was ending; but when one came straight from England the aspect of Barcelona was something startling and overwhelming. It was the first time that I had ever been in a town where the working class was in the saddle."

"Waiters and shop-walkers looked you in the face and treated you as an equal. Servile and even ceremonial forms of speech had temporarily disappeared. Nobody said 'Senor' or 'Don' or even 'Usted'; everyone called everyone else 'Comrade' and 'Thou,' and said 'Salud!' instead of 'Buenas Dias.' Tipping had been forbidden by law since the time of Primo de Rivera; almost my first experience was receiving a lecture from a hotel manager for trying to tip a lift-boy. There were no private motor cars, they had all been commandeered, and alll the trams and taxis and much of the other transport were painted red and black. The revolutionary posters were everywhere, flaming from the walls in clean reds and blues that made the few remaining advertisements look like daubs of mud. Down the Ramblas, the wide central artery of the town where crowds of people streamed constantly to and fro, the loud-speakers were bellowing revolutionary songs all day and far into the night."

"Yet so far as one could judge the people were contented and hopeful. There was no unemployment, and the price of living was still extremely low; you saw very few conspicuously destitute people, and no beggars except the gypsies. Above all, there was a belief in the revolution and the future, a feeling of having suddenly emerged into an era of equality and freedom. Human beings were trying to behave as human beings and not as cogs in the capitalist machine. In the barbers' shops were Anarchist notices (the barbers were mostly Anarchists) solemnly explaining that barbers were no longer slaves. In the streets were coloured posters appealing to prostitutes to stop being prostitutes."