Take a look at Carl Hiassen

Carl Hiassen portrays young protagonists that are willing to take action when it comes to righting a wrong. Among Hiassen's works are the bestselling Flush (2005) and, most recently Scat (January 2009). The film version of Hoot was released in 2006 but you really should look at the book if you want a good read.
Carl's official website is: http://www.carlhiassen