Shouting matches and even physical fights break out each time a mini-bus pulls up in downtown Harare as passengers battle to ensure they are not short-changed in coin-starved Zimbabwe. Hyperinflation forced Zimbabwe to trash its worthless local currency three years ago in a move that brought much needed relief to the crippled economy but created a surprising new headache: a lack of coins. "Change is a big problem, and at the same time passengers are impatient with us. I have been slapped a few times for not having change for them," said a bus conductor Walter Chakawata. The US dollar and the rand from neighbouring South Africa are Zimbabwe's main adopted currencies. The dollar, however, is preferred and all prices are pegged to it. But there is not enough US small change in circulation. The result is that prices are either rounded off -- making goods and services more expensive -- or customers brace themselves for a fight to get their change. The average city commute costs 50 cents. But the dearth of coins means passengers -- handing over bills -- are always owed change. Some bus drivers pair the passengers, handing them a dollar bill in change and leaving the two riders to sort the rest out themselves. Often their only alternative is to buy an item worth a dollar that they can then share -- a packet of cookies, a pie or anything they agree to.But that has not gone down well with many, who feel obliged to make an unnecessary purchase. Others complain it forces them to spend time with a total stranger. Or what if one is in a hurry? And in a country where many live on less than $2 a day, 50 cents still remains a decent sum, not to be wasted. The fights have at times turned deadly. Last year, independent papers reported that a state security agent pulled out a pistol and shot dead a bus conductor after he failed to give him change. In another incident, a conductor and passenger scuffling over change fell into a ditch with live electricity cables and were both electrocuted. Initially, drivers issued credit notes in the form of coupons but they were not universal and only valid on specific routes. Bus operators also ran into problems with fake coupons, on some days accumulating nothing but paper slips and not enough cash to pay for their fuel. To get round the problem, a South African five rand coin has become widely accepted as equivalent to 50 cents, for the purposes of public transport, regardless of the actual exchange rate. This in turn has prompted entrepreneurial-minded young men to smuggle in coins from South Africa to sell to bus conductors. "We have agreed with the Kombi (minibus) drivers to split the dollar into rands, so they come here to get change," said Felix Munonyanya, a boilermaker who found the trade lucrative enough to quit his job of six years to sell rands on the roadside near the main working-class suburbs of Mbare and Highfields. Not all merchants buy coins, however. Ice-cream and yoghurt vendor Locadia Chimimba conceded that "the situation is better these days because you can buy change if you want" but she herself does not and still asks customers to buy more to make up the difference. In supermarkets, when the grocery bill does not add up neatly to a round figure shoppers are offered sweets, match boxes, chewing gum and even condoms to compensate. Credit notes have been another option, but Zimbabweans complain they are often printed on thermal paper that fades easily. The country's mobile phone services have stepped into the picture, offering airtime in lieu of change. Dubbed Yo-Time, supermarkets can instantly credit a customer's pre-paid mobile with any value from 10 cents and $50. "When we realised there was a problem of change, we thought, why not have it paid out as airtime so that people were not forced to buy sweets," said Yo-Time's creative director Walter Chipangura. "We were getting tired of sweets!" So far, all sides seem pleased. "It has reduced the pressure. There used to be lots of shouting," said Farai Doka, manager of Spar supermarket in the middleclass Kensington suburb. Authorities considered importing US coins but the idea was dropped when shipping costs proved too expensive -- costing two dollars for a batch of coins worth one dollar, experts said. Two years ago bankers imported eight million rands worth of coins, but these were rejected by retailers as they haggled over the exchange rate. Ecuador, which also uses the US dollar as legal tender, uses coins of its own currency in place of US cents. But trying to mint and re-introduce Zimbabwean dollar coins is likely to bring back painful memories and meet resistance. During the economic meltdown, it took sackfuls of notes just to buy groceries and millions lost their savings as the currency became worthless overnight. "For me, I never want to see the Zimbabwe dollar again," said Patrick Nyakodzwe, selling airtime scratch cards and packets of biscuits for one rand each near the city's Copacana bus stop.