David Bach, the author of "Go Green, Live Rich", first coined "The Latte Factor" a years ago.  It applies to all of the small items we buy on a daily basis.  Things like coffee in single-use cups, designer bottled water, soda, cigarettes, etc.  He said that while these are small purchases, they add up in the long-term.  On a similar vein, "The Litter Factor" allows you take a look at your trash.  Take a look at your office trash, your home trash and each time you stop on the street to throw away something.  What is most common in that trash?  Is it really something that you need?  Is it something that you can avoid?  Is it something that you can replace with something more sustainable?