title: Create Form Auto Complete in Google App Engine
body: <p>I want to build a auto complete feature for a tags field like in SO on App Engine ... any idea how I should go about the process?</p>
  
  <p>Server Side Algo? - What logic should be there for auto-complete?</p>
  
  <p>App Engine implementation? - What should be the Datastore schema for this? </p>