Parallax Boe Bot Crawler might be one of the most simple legged robot. It uses only 2 motor servo and moves forward, backward, turn left or right, only by controlling run/stop of the servos with a very simple programming. So, we consider this is a good start to introduce a type of legged robot to elementary/junior high school students in Indonesia.
This Parallax kit consist of:
1. Boe bot chassis (default with wheels)
2. Crawler kit
3. Two motor servos
4. Basic stamp micro education board
5. Some sensors (infrared, whiskler)
6. USB cable programming
7. Education book (very comprehensive)
8. CD software (BS compiler & downloader)
This kind of legged robot is introduced after our lesson about wheel robots. The crawler movement is like... grasshopper (funny enough). The children like to assemble and playing around (with a simple programming of course).
Although it's design has some limitations, but we think it is good enough as a start before understanding other complicated structure/movement of legged robot such as "real hexabot".