A gang of streetwise teenagers from Dublin's Liberties area poured into a local butcher shop last week and demanded to know whether the ham was locally sourced.
Satisfied it was indeed Irish, the teenagers handed over their cash.
"The butcher had a good laugh about it," said Niamh Geoghegan, a programme co-ordinator for the Digital Hub, the hi-tech learning centre beside the Guinness Storehouse. "But we thought it was a good way to teach them about carbon footprints."
The Liberties teenagers now know it's more environmentally sound to put Irish pork in their sandwiches than meat flown in from elsewhere.
The exercise was part of a free, week-long, hi-tech programme called iTrek that aimed to raise the environmental awareness and digital skills of young inner-city Dubliners.
Armed with sponsors' laptops, 3G mobile phones and computer programs like Photoshop, 20 teenagers took part in a kind of environmental boot camp.
Phil Finnegan (15) said he had taken at least one message on board. "We learned about recycling - not to throw rubbish on the ground," said Phil. "After they showed us about what happens to all the rubbish on the ground, they took us into the mountains."
They set up camp in an 80-acre forest in Larch Hill, near Rathfarnham. It was the first time Phil and his James's Street friends Philip Christian and Dean Graham had camped out.
"It was just great to get outdoors and stay out, have a laugh," said Phil. "Three mates in the outdoors - you can't ask anything better." Performer Rosie O'Regan dressed as characters such as "Biodiva" and "Cruella Oil" to enliven global warming and noise pollution.
Biodiva blindfolded a group of Liberties teenagers and led them in silence through Phoenix Park. They used "green" transport - like the Luas or a pedal-powered ecocab - and got to enjoy an unlittered landscape.
Many of the teenages are tech-savvy. Ross Mooney (16) spends time at a computer club run by the South-West Inner City Network. He said he was considering a career in game design. "It's the future."
Alan Walsh, youth services manager at the network, said most users of the computer club don't realise they're learning while using the computers.
"It's a backdoor way to teach them about game design and programming."