http://beersmith.com/blog/2008/06/25/enhancing-beer-head-retention-for-home-brewers/
Read the full article..but in a Nutshell
""Head stability depends on the presence of substances with low surface tension in the beer which can form stable elastic bubbles. The two primary contributors to head retention are certain high molecular weight proteins and isohumulones (alpha acids from hops). Therefore beers with more proteins that are highly hopped will have higher head retention.
Methods for Improving Head Retention
We will explore the following possibilities:
The use of body and head enhancing malts such as crystal, wheat, or carafoam
The altering of the mash schedule to enhance head retaining proteins
The use of heading agents additives that enhance head retention
Addition of high alpha hops which will increase bitterness, but also increas isohumulones that enhance head retention
Limiting the use of household soaps on drinking glasses and homebrew equipment
The use of a nitrogen and CO2 mix for carbonation and serving
The shape of the glass used to serve the beer
Head Enhancing Malts
The inclusion of proteins and dextrines enhance the body and head retention of finished beer. Unfortunately when used to excess, proteins and dextrines can interact with tannins and reduce clarity and promote cloudiness, so a proper balance must be struck. Crystal malts to include the light Carapils and Carafoam, and caramel malts."