I found this little gem a while back. http://www.amazon.ca/Mail-Order-Mysteries-Real-Stuff-Comic/dp/160887026X
For anyone who grew up on American comic books in the 70s, this book is a lot of fun. The author collected many of the items advertised in the back of the book and revealed what they are actually like. (X-Ray Specs, Grit Newspapers, Spy-pens, and much, much more.) Its a fun trip down memory lane, and deeply satisfying to know what these things actually turned out to be.
The author is Kirk Demarais, and the afterward is written by Jesse Thorn, for those of you who are Maximum Fun listeners.