For an upcoming article, I am assembling a list of the top online learning Web sites for kids under 10. Care to submit one? or a few? I am including Web sites that nurture creativity in some way as well.
Here is what I need:

Name URL If you can, it would be great to know the following
Free or paid
How your child or acquaintance used it
The benefit you perceive he/she received.
Thanks..

EXAMPLES OF THE INPUT I AM SEEKING
Pbskids.org
Has many educational games based around their educational programs. Navigable (for the most part) by a five year old. My oldest began visiting the site when he still pronounced “PBSKids-dot-gord” and learned a host of basic concepts (matching, sequence) and importantly, the basics of interacting with a browser and keyboard…

Toonlet.com
A more complex site that lets anyone build comics and characters. Not a kids site but for the older child (8yo and up maybe), challenges their mind (have to figure out the platform) and encourages creativity. Kids may need some help getting started.