A spokesperson for Trailfinders, the travel firm, says: "In Zimbabwe, people seem to want clothes with writing on, particularly T-shirts. I traded a T-shirt for a hand-carved wooden sculpture. In Malawi, I swapped a cheap calculator that I had been given in a promotion for a chieftain's chair."
Traveller Jackie Blyth has a salutary tale for Brits who think all foreigners are stupid. "I went on a trip to Kenya," she says. "The thing to watch there are the bus tour guides who often stop the coach for refreshments in a place full of hand-made items.
"It is there that they pounce on your saying, 'You can have anything in the room for your hat.' But after getting your hat they will ask for shillings to get the thing you want. I've seen people leaving without the hat, T-shirt and socks they came in."