From the NASA EXPRESS email list:

Spring 2008 Cassini Scientist for a Day Contest

The Cassini Scientist for a Day contest challenges students to become NASA scientists studying Saturn. Participants are challenged to examine three target images taken by Cassini and choose the one that they think will yield the best scientific results. This choice must then be explained in a 500-word essay.

The contest is open to all students in the United States from grades 5-12, working alone or in groups of up to four students. The essays will be divided into three groups: grades 5-6, 7-8 and 9-12. All submissions must be students' original work. Each student can submit only one entry.

Deadline for Spring 2008 submissions is noon Pacific time (3 p.m. EDT) on May 8, 2008. For more information, visit http://saturn.jpl.nasa.gov/education/scientist/. If you have questions about this contest, please e-mail your inquiries to scientistforaday@jpl.nasa.gov.

Spring 2008 is the fifth edition of Cassini Scientist for a Day. See also the results of the fourth edition in fall 2008 at the JPL web site.

Students in the US in grades 5 through 12 have a chance to be a Cassini Scientist for a Day. The Cassini team has selected four targets for future study of Saturn's moons and rings. Students choose one of the targets and justify why they would study it in further detail in an essay. The winners get to see their scientific missions realized by Cassini. I like that prize -- not money, but respect for your scientific thinking.

Link: http://saturn.jpl.nasa.gov/education/scientist
Deadline: 15 November

If I were in that age group, I'd be all over this. Working at JPL is the only constant "what I want to do with my life" since... well... my whole life. On the off chance that you're a student or a teacher that sees this post, leave a comment, and I'll try to find someone through the AAS or SEDS networks to help you with your entry. It would be a great opportunity to learn about a great exploration mission.