Intructional video:

http://www.youtube.com/watch?v=nHXcibEJ1lc

Further details from the Grilling Guru:

http://www.firepit-and-grilling-guru.com/charcoal-chimney.html

A few models for sale:

http://www.google.com/products?sourceid=navclient&rlz=1T4GGLD_enUS311US311&q=charcoal+chimney&um=1&ie=UTF-8&ei=Nn0ISsKqGovhtgeS-