Some ideas for a holiday that makes a difference:

  • Working holidays: The National Trust, The British Trust of Conservation Volunteers, the Waterways Recovery Group all run structured working holidays in the UK on which you can work on a conservation project by day and socialise by night. You'll gain new skills (drystone walling anyone?) and meet new people in fantastic locations. And it's cheap - a small fee for food and accomodation is all it will cost, unless it's your round at the pub!
  • BTCV also run working holidays abroad