Amidst many strong and detailed government websites, the National Aeronautics and Space Administration (NASA) site always presents a rich variety of material for the space-curious public. Their "Interactive Features" area is embedded in their larger "Multimedia" site, and it's a fantastic kaleidoscope of sweeping views of Saturn, fun with the X-15 spacecraft, and more than a few (several dozen, actually) interactive timelines. First-time users can browse through the archive of features at their leisure, or they can also use the search engine to look for specific items. Some of the more noteworthy features here include a timeline which explores the history of "planet hunting" ("PlanetQuest Historic Timeline") and the trip through space in the "Virtual Lunar Outpost". It's easy to while away a few hours on the site and it is one that budding space scientists will want to bookmark.