Ballooning in the UK as looked after by the British Balloon and airship club.
http://www.bbac.org/
take a look in Affiliated Organisations for "Geographially Based Groups"
http://www.bbac.org/affil.php
If you contact a regional group & show up at a few meetings then you'll meet some local balloonists. Balloonists are often on the lookout for people who are prepared to turn out at dawn to help launch, pack & retrieve the balloons. It helps if you are over 25, have a driving licence & are happy to drive with a trailer, have a few basic social skills and are either very strong or very good looking!
Expect to have to go out crewing 2 or 3 times before you get a flight, and once you've had one offer to buy the first round in the pub after!
Dave