Use a Rake task.
In Lib/tasks, make this file
In that file, put this code:
namespace :db do
desc “Boostrap my database with default data”
task :import => :environment do
User.create :login => "admin", :password=>"admin", :password_confirmation=>"admin", email=>"email@example.com"
other cool ruby code goes here
Then, as part of your deployment,
rake RAILS_ENV=“production” db:import
(make that part of your deployment recipe if you wish!)
Hope that helps!