Object Calisthenics is an idea suggest by Jeff Bay in The ThoughtWorks Anthology , and lists 9 rules to writing better Object Oriented code. For those who haven’t seen the book, the 9 rules are:

 # Use only one level of indentation per method
 # Don’t use the else keyword
 # Wrap all primitives and strings
 # Use only one dot per line
 # Don’t abbreviate
 # Keep all entities small
 # Don’t use any classes with more than two instance variables
 # Use first-class collections
 # Don’t use any getters/setters/properties
  
http://www.markhneedham.com/blog/2008/11/06/object-calisthenics-first-thoughts/