I've started to gather links for the all-school study, and I'm sure this entry will be updated many times as the committee finds new stuff. Feel free to email me new links as you find them, and I will add them.

South Korea - an introduction.

Kids Eyes On Korea - a slideshow made by students in Australia.

Pororo - a site with games and activities in English and Korean. Based on a popular Korean cartoon character.

Korea for Kids - a site with number and word games in korean 

You can also visit CultureGrams in the Recommended Links menu on the left.