Nice blog. I made a simple hovercraft for my 4 year old son this weekend with plywood a leaf blower and shower curtain. He learned about air pressure. Cool stuff! We found a fun site with neat science experiments like simple hovercraft directions. I will put the link below for anyone interested.
http://weirdsciencekids.com/FunExperiments.html
It technically doesn't hover since it touches the ground at times but its difficult to have a perfect distribution of the weight.