<p>I did Projects Abroad a couple years ago when I was 16 (youngest age they took). They offer tons of different projects in many different countries. I loved my experience and actually ended up extending my trip once I was there (5 weeks total). If I recall correctly, they have special programs for teens but I passed those up because they looked too vacation-y. However, I did their normal volunteer program which allows the volunteers entire freedom in duration of volunteering and I think provides for a very good experience.</p>
<p>If you want more information, feel free to PM me.</p>