I once read personal ad in Sailplane & Gliding magazine about such exchange of youngsters, or rather, someone looking for family to adopt them for summer. Not exactly heavy RT in the gliding scene, but aviation and low cost fun, nonetheless.
If you want to spend summer in the UK and have or would like to have exposure to gliding, then ask the big gliding clubs. They always need 'helping hand' and you should get some rides in private two-seaters or low cost gliding lessons (winch launch, cheaper but thrilling in the beginning). Lasham, Booker, Bidford, Deeside/Aboyne (->Scotland, cannae geddit oot yer heid) would be the bigger ones.
http://www.gliding.co.uk Big clubs would tend to have basic on-site housing as well.
Alternatively,
LiveATC.net is useful website for airport frequencies. Some may be bit daunting (and showing you the real life), i.e. New York approach, some more relaxed, but if elsewhere around the globe, you should check the local time of day.
Oh la la, finally French fast jet jocks are required to have good aviation English?
