Coding for Kids
codingforkids.org
codingforkids.org
Guzdial's work is aimed at teaching programming to undergrads (who may or may not be CS majors) but would make a great starting point/inspiration for designing something for younger kids.
Other things that might be interesting:
Alice: http://alice.org/
Hackety-Hack/Shoes (please come back, _why... we miss you :-): http://hackety-hack.com/ http://www.shoesrb.com/
The Inform 7 system for creating interactive fiction: http://inform7.com/
Scripting languages for virtual world software, e.g., the Linden Scripting Language for Second Life/Open Sim -- it's a nasty, nasty language (even its designer agrees :-) but lets you do some really powerful and impressive things:
http://wiki.secondlife.com/wiki/LSL_Portal http://opensimulator.org/wiki/Main_Page
Open Cobalt: http://www.opencobalt.org/
Open Wonderland: http://openwonderland.org/
I used to teach a course covering this stuff which was designed for teachers:
http://contraterrene.com/course_outlines/VirtualWorldsOutlin...