Foreign exchanges of school children seems looks likely to become a thing of the past, at least in the UK, as families who host foreign children will have to have criminal records checks by a new Independent Screening Authority from next year. This is because a Home Office report in the late 1990s showed that a very small number of foreign children had been hosted in the homes of British sex offenders. The criminal record checks are expensive and will deter many potential host families.
This seems a shame as such exchanges are a great way for children to experience foreign cultures in a family setting, to get a taste of foreign food, and most importantly, to improve their foreign language skills. There are many in other European countries who would like to come to the UK on exchange visits, but the number of children studying foreign languages here is decreasing, so there is a shortage of potential exchange partners here.
While I was at school I went on an exchange visit to France and stayed with a large family in a village in eastern France. The family also had apartments in Paris, where I spent part of the visit, and my exchange partner came to stay with us in the UK after I'd been in France. I enjoyed this experience and it helped my French a lot. I also got to ride little motor scooters, and discovered the delights of fresh French bread with chocolate as an afternoon snack. Other visits I went on the Germany and Austria were also interesting and enjoyable, but didn't involve my exchange partners coming back to the UK. These exchanges and visits were arranged via family friends or teachers at school.
Exchanges don't have to be confined to school children though - there are ways for adults to arrange something similar. For example, CouchSurfing is a network of people who are willing to put up others in their homes, and who can stay with members of the network when they go travelling. You can specify that you prefer to host speakers of particular languages, so it's a good way to make new friends, practise languages you're learning, and learn about foreign countries and countries. It's also free and has over a million members who between them speak over a thousand different languages.
There are a number of other organisations and networks which help you arrange foreign exchange, such as Foreign exchanges. Some focus on language learning, others on cultural exchange, which can include language learning.