Marvin

Well this is not really freeware but is heavily subsidised by the mined. there is just a admin fee of $200 for 5years i think. you can install it on all teacher, classroom, personal computer and it can be sent come home with kids to install at home.
Marvin is a 3D presentation tool supported by Microsoft.
you have a variety of characters to choose from. People through to cartoon characters. in all about 100.
You can animate these characters with there preset animations. Have a look at my demo that i did for church.
It was introduced at Learning@schools as a kids friendly program. But it is actually more for year 6 up. It is not as easy as they make out.
one plus with this software is once you are done you can export it as a AVI file so it will run on any machine. One problem with this is that not all computers support the AI codec that it uses.

In all, a neat program to play with but I'm not convinced it is usable to a large extent in the classroom.
One of the niggles is that the character all have different animations. Some of the basic functions like walk, point, wave... are not included in each character.
the other is that it takes a grunty machine to publish it as a decent AVI. Even my teacher lap top struggled on the lowest quality setting.

If you want to know more go to Mavin's website http://www.marvin.com.au/ look for the education section.