Heard the one about the German, the Italian and the Briton who were all on holiday in France? They went to the cash machine to take out some euros, and only the traveller from Britain had to pay extra for the transaction.
It's not that funny really. And as charges for credit and debit cards come under increasing scrutiny, the rake-off paid by British holidaymakers for overseas card transactions is the latest item in the small print to be challenged.
This attack on card charges is being made on two fronts. First, there are accusations that the "administration" or "handling" fee, typically around 2.75%, is boosting profits rather than covering the cost of currency exchange.
The second complaint is that consumers in Britain are not benefiting from the European Union regulations which have banned extra charges for cross-border cash withdrawals of euros.
The consumer-friendly MP for Brent North, Barry Gardiner, has raised this question in parliament.
"This is nothing less than a tax on holidays. The European regulations are clearly drafted to stop banks charging you more for withdrawing cash outside your own country. British banks must explain why they are adding this extra transaction fee on top of the profits they are already making on foreign exchange rates. These are the holiday highwaymen of the 21st century," says Mr Gardiner.
The European regulation in question says that consumers taking out euros from a cashtill in another European Union country should not have to pay any more than they pay to take out money at home.
This law applies as much in Britain as in the rest of the European Union, but the big sticking point, and the reason that we don't benefit from the ruling, is that at present there is no way of taking out euros from a cash machine in Britain.
As such, banks in Britain can legitimately say they're not charging us any more to take out euros from cash machines when we're travelling, because there is no comparative figure for withdrawing euros from cash machines when we're at home.
British banks and card companies will also say that none of this is relevant, because unlike banks in the eurozone, their charges are concerned with currency exchange, not just taking out the same currency across a border.
But this argument, that the 2.75% foreign exchange charge is a fair reflection of conversion costs, is rejected out of hand by the Nationwide, which has broken ranks with other card issuers.
Nationwide says these extra charges, wrapped up in the currency conversion process, are a smokescreen for banks and card companies to trouser a hefty profit, which it estimates at £350m this year, from travellers using their plastic.
According to the Nationwide, when its customers use their cards to take out money in Europe, the currency conversion is carried out through Visa, which offers a "wholesale" currency rate that is substantially better than is available through a high street bureau de change.
This rate is passed on to the customers who get their euros from the cash machine. And, er, that's it. The extra 2.75% "administration" charge levied by other banks is nothing but profit, says the Nationwide.
The banks and card companies say that the increasing use of credit and debit cards abroad reflects that they are convenient and good value for customers on holiday and that there are extra costs in allowing customers access to an international ATM network.
Barclaycard says that taking out money with a credit card is still cheaper than through a bureau de change and that the reason that charges are under attack is because card companies are so transparent about their fees.
While a bureau de change will disguise its commission in an unfavourable exchange rate, the credit card companies have to separately itemise the currency exchange and its additional fee. And it says there is nothing wrong with a business having a profit margin on a convenient and competitive service.
Lloyds TSB echoes this position, saying that its customers are getting a useful service that is good value for anyone taking out money when on holiday.
But such charges seem increasingly outdated when travel to Europe has become commonplace.
When the cash advance fee is added, British travellers can be losing 4.5% on every euro withdrawal - and this figure can be much higher on small withdrawals, where a minimum charge of up to £2.50 can be applied. If you were taking out a tenner's worth of euros to pay for a taxi to the airport, the charges could be over 25% of the value.
The European regulation on cutting card fees is also throwing up anomalies. There has been a big growth in British people buying second homes in places such as Spain and France - and many of these will have opened local bank accounts.
For these Britons abroad, if they use their Spanish or French cards when they're in another European country, they can't be charged extra - but if they use their British bank card they'll have to pay a fee.
Customers of a European arm of a British card company also won't pay.
There are signs that the card industry itself is recognising that such charges might not be able to survive in the long term.
Sandra Quinn of the Association of Payment Clearing Services (Apacs) says that card companies are entitled to charge a fee for foreign currency transactions. But she says that there are clear trends for more regular travel and greater transparency over fees, which could lead to keener competition over such foreign exchange charges.
