nanoreisen:Adventures Beyond the Decimal allows the viewer to travel deep inside some common objects. It's a great and beautiful demonstration of our "inner" universe. Try a voyage.
SparkTop.org is a rich site designed for 8-12 year old students with learning disabilities. The site includes games, information on coping with disabilites, and some communication tools. My favorite activity is the Audio Mixer in the "Create" section. It's like a mini GarageBand. SparkTop.org is one of the finalists in the Flashforward 2005 film Festival.
GollyGee Blocks is a very cool 3D building block program for young kids. The very simple and straight forward interface makes it easy to construct 3D structures. With the variety of objects included, kids can create landscapes-parks, farms, space scenes, and many others. Kids can view their creations from a variety of perspectives by changing "camera" angles. A great tool for helping kids develop a sense of perspective. Thanks to David of Devotion School.
I didn't realize that The Educational Software Preview Guide (ESPG) was available online. This former print-only guide is a collection of educational software that's been favorably reviewed. Software reviews are not included, the ESPG serves as a source for software titles with links to the publishers. This searchable database of over 1,000 titles is a great tool for seeing what's available in each curriculum area. You can find the Guide here