My Take
This is a great site to use when your students have downtime. It's fun and interactive and offers a number of games at varying levels. It also has the scientific aspect of by offering various video clips, pictures and articles on a number of scientific topics. What I like the most is they offer the visual aspect that many students need to help reinforce their learning.
How I Use It
This site offers fun science games for younger students. They have multiple levels of difficulty as well as a number of fun interactive games. They also offer links to various multimedia, current missions and information about NASA. It has good graphics and visuals which help students to make the connections to what they are learning about as well. One thing that really stuck out was that they offer a weekly report from the lead scientist of the international space station. That could be used as a weekly lesson in class.