Berlin officials plan to introduce litter bins that say "thank you" when you deposit your rubbish in them.
Much of central Berlin has been transformed since 1989
About 20 of the hi-tech, solar-powered bins will appear on the city's streets in April, in a drive to raise people's awareness of the litter problem.
But they will not look very different from the existing 20,300 bins in the German capital, a spokesman for the city's cleaning service said.
"The bin should become a sympathetic partner," said Bernd Mueller.
The prototype bins are designed to be "fun" - each one can be programmed to say different things, even in other languages, Mr Mueller told BBC News Online.
"The idea is to raise people's awareness," he said.
The batteries installed in the bins will also illuminate them at night.
Mr Mueller said Berlin's litter problem was not substantially worse than in other cities, but "every city wants to make itself more attractive to visitors".
The new bins "will not be hugely expensive," he said - no minor consideration in a city suffering from chronic debts.
But there are no plans yet to mass-produce them.
The Berlin authorities have cut subsidies for cultural institutions, faced with crippling debts of nearly 50bn euros ($61bn).
Since the fall of the Berlin Wall in 1989, the city has had the reputation of being Europe's "biggest building site", undergoing a dramatic transformation as it recovers its former glory.
But Germany's powerful Green movement has maintained the pressure to keep the capital's streets tidy and traffic congestion has been reduced to a minimum.