title: STI where children include parent records (Rails 4)
body: <p>BACKGROUND: I have City model and I'd like users to be able to select both a Hometown and a Current City from the master list of Cities, so as to be able to call user.hometown and user.currentcities as methods.</p>
  
  <p>QUESTION: What are some approaches for best tackling this scenario?</p>
  
  <p><strong>UPDATE</strong>
  I forgot to mention that City is itself a type of Community (there are other types of communities users can select besides City) - which is why I'm using STI.</p>