A few years ago, 14-year-old Laura Dekker took off from her home in Holland and became the youngest person to circumnavigate the globe singlehanded. This is her [kick-ass] story.
iTunes has the documentary of the voyage, called Maidentrip, available for a buck this week.
Even if you have nothing to do with the water, this is a great movie, considered by sailors to be the best sailing documentary out there. Well worth the buck. I'll also recommend this for anyone interested in my upcoming AMA on sailing, surfing, and ocean-related matters (and linguistics).