You could work with the Bahamas National Trust to survey the Island's valuable reef and its inhabitants and become a trained PADI scuba diver while you work. Other opportunities available are trekking in Borneo, working on medical projects in Ecuador or training to become a ski instructor.
Some inspiration from Gapforce (see their blog for first hand accounts) could help you decide what you want to do or sign up for their open day on 4th June in London.
Or you could meet VSO this evening in London and talk to volunteers and staff about what opportunities are available on their open evening. The VSO has two youth programmes aimed at ages 18-25.
If fashion is more your style, then the Fashion Retail Academy has an open day on May 18th where they aim to provide truly vocational education through full time courses and work placements right in the heart of London's fashion arena just off Oxford Street.
Please make sure you register online for any of the open days.