Rails - Jul 2006 - ActiveRecord question

Hi everyone,

I am having the following problem:  I have a ''User'' model and
a
''User_option'' model (user has_many user_options &
user_options
belongs_to user).
Now the user_option table (and model) consist mostly of a key & value 
fields, and I would like to be able to reference them like an 
associative array
instead of a collection.  Here is what I mean:

user = User.find(:first)
user.user_options[:key]

instead of having to do:
user.user_options.find {|option| option.key==key}


Someone suggested I should do it like this:

class User < ActiveRecord::Base
  has_many :user_options do
    def [](key)
      user_options.find {|opt| opt.key==key} #(search code)
    end
  end
end

The problem is the user_options array is not visible from within the 
method because the method is in effect
inside the user_option class(model).  So I am wondering how I can 
reference the ''outter'' class User from within the
method ''def [](key)''.  Is this possible?  The purpose of
reusing the
user_options array is that I don''t have to deal directly with the
database.

Any help would be greatly appreciated...or any other suggestion on a way 
to accomplish the ''user.user_options[:key]'' thing.

Thank you,

Jd