Foraging: onion weed

We're foraging for more free food with Johanna Knox. This week, onion weed's a bit like a wild spring onion and good in dips, breads, marinades and Asian cooking.

History of the zip

Zips are on everything nowadays. But the idea took about 40 years to get off the ground, two world wars got in the way, and tragedy struck one of its main inventors. Robert Friedel charts the history of the zipper.

Non-melting chocolate

Gaby Tschofen of the Swiss chocolatier Barry Callebaut reckons they've cracked the secret of heat resistant, low calorie chocolate.

Hi-tech chocolate

We're off to San Francisco where Cyrus Farivar's visited a new producer using all sorts of hi-tech wizardry in the chocolate manufacturing process.

World's biggest gambling den

The southern Chinese city of Macau makes more money from gambling than Las Vegas and Atlantic City combined! Clifford Coonan's seen some changes in the 20 years he's bene visiting.

Tech news: music downloading

Bill Thompson on a new UK study of music downloading and young people's listening habits. Plus the US employers facing lawsuits from"hyperconnected"workers.

Tracking your rubbish

Trash Track's the name of a project in the US that's using location tags to track the journey your rubbish takes after you leave it on the kerbside. Assaf Biderman of MIT's leading the project.

Crustacean colourings

Dr Nick Wade's one of the Australian scientists who reckons they've solved the mystery of what makes crabs, prawns and lobsters change colour when you cook them.