In their own words…
“MadSci Network represents a collective cranium of scientists providing answers to your questions. For good measure we provide a variety of oddities and other ends as well.”
In addition to their library and a search engine that will help you find scientific information on their own site and the world wide web, they have amassed a small collection of science experiments “that require little more than a quick rummaging through the kitchen cabinets.”
If you have an experiment that you would like to share with others, you can submit your ideas to using their on-line submission form.
They also provide links to a large number of scientific demonstrations for different age levels. Be aware that some of the links are no longer viable (e.g., Student Alleles Database).