This is a magnificent online connection for any intelligent kid who can't get enough math and science-and who wants to expand his or her interests and academic horizons beyond the classroom rigors, from computer animation to global warming.

Developed and maintained by the Johns Hopkins Center for Talented Youth, this smart and easy-to-navigate site is above and beyond the call of curiosity for youngsters who demand more to think about. Cogito is Latin for "I think," after all, and this site echoes Descartes' famous observation: "Cogito ergo sum," or "I think, therefore I am."

Through a navigation bar, users can connect to interviews, news, other select science websites, educational programs online and off, and a calendar of events. The drop-down menu under News & Views, for instance, offers categories from "Young Scientists" and "Webcasts" to "Books and Movies" and "Creative Writing." Under the Sites & Tools category, users find links to scientific websites, blogs, free online course materials, news sources and research tools-all of it free.

At the top of Cogito's main page, several "Spotlight" features rotate regularly. On one recent day, the Spotlights included a Q&A with UCLA physicist David Saltzberg, who is a technical advisor to the CBS-TV comedy "The Big Bang Theory," and an interview with University of Iowa cognitive psychologist Shaun Vecera on visual perception and optical illusions. These and the many other interviews on Cogito with Internationally-renown researchers and scientists even allow users to submit questions.

Other fascinating stuff abounds, from a PBS video interview with bestselling scientists Oliver Sacks on the power of music to a story about a North Carolina student (Cogito loves stories about students digging deep) researching mercury sulfide nanoparticles in fresh water from Alaska to Sweden. More fun on the Cogito Gallery where full-color high-quality photos challenge users to answer "What is it?" And for focused users, Cogito's "channels" filter specific content from this vast and loaded site, so if a young Einstein wants to focus on the world of biochemisty, he or she can filter out everything else.

Cogito is also a great resource on distance-learning programs for budding scientists and summer programs as well. And it keeps a continuing list of science and math competitions (190 listed recently) open to upstart scientists.

Anyone can visit Cogito and explore its vast content and resources, though some of the site (participating in forums and commenting on articles) is limited to members only who must be invited by Cogito's partners (such as the Center for Excellence in Education) or affiliates (such as American Mathematics Competitions).

Cogito does the right thing in terms of privacy (asks for no personal information from non-members; invites members fill out a profile that's kept private). Not only does Cogito cost nothing, no ads or promos distract from its rich scientific content. For any teen fixated on math or science, this is a must-see site, potentially a regular hangout.