If you are an educator with access to an interactive whiteboard and can integrate a visit to Mars into your lesson plans during the last days of the school year, a trip to the Phoenix Mars Mission website is a must! The website is well designed and user-friendly.
Renderings of the Phoenix Mars Lander
Here are few places to start:
Phoenix Mars Mission News
Web Exhibit -Mars: The Search for Water, the Search for Life
Flash Video Stream (the video has relaxing ambient music, by the way)
Videos and Animations
Just for Kids - this site was designed with content by kids to share with others.
From Mars to Earth: An Interactive Timeline