Rails include YAML.rb somewhere, so we have access to the to_yaml method on any object.

To see what's in an object, define a helper:

<pre>
def dump(object)
  "<pre>" << object.to_yaml << "</pre>"
end
</pre>

Then in your rhtml, you can do a:

<pre>
<%= dump @person %>
<%= dump @person.methods.sort %>
</pre>

Which may yield something like:
<pre>
--- &id001 !ruby/object:Person 
attributes: 
  name: Superman
  city: Smallville
  zip: "12345"
  street1: PO Box 123
  street2: 123 Somewhere
  id: 1
  state: KS
errors: !ruby/object:ActiveRecord::Errors 
  base: *id001
  errors: {}
phones: 
  - !ruby/object:Phone 
    attributes: 
      id: "1"
      phone: "6203423065"
      person_id: "1"
  - !ruby/object:Phone 
    attributes: 
      id: "2"
      phone: "6204811303"
      person_id: "1"
</pre>