I haven't used rails with postgres views, but this wiki article may help you along:
http://wiki.rubyonrails.org/rails/pages/HowtoUsePostgresViewsAsTables
plus this article show how views can be used for R, but no CUD. mmmm. chew. mmmm.
http://johnwilger.com/2005/9/29/class-table-inheritance-in-rails-with-postgresql
cheers, Jodi