Business Opportunities: Consumer Information
   Federal Trade Commission site with tips on how to avoid scams. Most files are in PDF.
   http://www.ftc.gov/bcp/conline/edcams/bizopps/coninfo.html

Shaking the Money Tree
   Online article by Ami Shen Lee exposes the pitfalls of multilevel marketing.
   http://www.metroactive.com/papers/metro/10.03.96/cover/multilevel-9640.html

Suspected Pyramid Schemes
   Oregon Department of Justice site with information, hotline, and complaint form.
   http://www.doj.state.or.us/finfraud/pyramids.shtml

What's Wrong with Multi-Level Marketing?
   Provides an in-depth analysis of MLM and areas to be avoided. Includes links to anti-MLM research and information.
   http://www.vandruff.com/mlm.html