At the end of your Rapid Prototyping talk @ CCC, someone asked about
making garbage bags. When I was in high school, I attended a "machine
tool" summer camp (which was a *lot* more fun than math camp!) @
niu.edu. While I was there, I learned how to make garbage bags.
The process is a lot like web printing (the type of printing presses
used by newspapers), i.e. it's really not practical to do a "few" bags.
FYI- here's a mid sized machine:
http://plastic.machinery.com.tw/film-extrusion/lldpe/LLDPE-TAT.htm
cheers,
glenn
enjoy,
glenn