[This is a guest post by Kristin Underwood. -Ed] Got a great idea for how to tell other teens about saving the planet? Enjoy seeing the TreehuggerTV videos, but think you have a better idea? Well, this is your lucky day! Seventeen Magazine and Myspace.com are hosting a Public Service Announcement Video Contest where you can create a 30 second public service announcement on your favorite cause. This is a great opportunity to tell everyone about why saving the planet is so important and we have has tons of great tips and ideas to help you get started in our archives. Entries are due August 15th, so start planning now!