Vacuum Cleaner Resources

During the course of our Internet research we sometimes run across quality sources of vacuum cleaner related information.  These are recorded here and the list will continue to grow.

Lists of the top consumer-rated vacuum cleaners from each category (upright, canister, stick, handheld, etc)
http://www.top-rated-vacuum-cleaners.com/

Some good descriptions of the different kinds of vacuums and some history:
http://en.wikipedia.org/wiki/Vacuum_cleaner

Lots of educational material on vacuum cleaners and details on certain makes and models:
http://www.ristenbatt.com/edu.mv

Good article on how vacuum cleaners work:
http://www.howstuffworks.com/vacuum-cleaner.htm