One last Ruby question for tonight - Regarding UUID type

My goal is to learn Ruby by porting one of my existing PG web
applications over to Rails..  However, my existing data heavily relies
on the UUID data type.  I've noticed when I create a new model with
something like:

guidtest name:string value:uuid

And then do a rake:migrate, the CREATE TABLE that gets generated looks like:

CREATE TABLE guidtests
(
  id serial NOT NULL,
  "name" character varying(255),
  created_at timestamp without time zone,
  updated_at timestamp without time zone,
  CONSTRAINT guidtests_pkey PRIMARY KEY (id)
)
...

In other words, it just ignores my "uuid" type.  However, the views
and stuff do include this column so the page will crash when I load it
since the column doesn't exist in the DB.

Is there some special thing I have to do to use the uuid type in
ActiveRecord?  Thanks!