I use the following Capistrano script to manage deployment of my blog to Dreamhost. It is a modified version of the deploy script provided on the Radiant CMS wiki, and it addresses two bugs involving the svn username and password.

To use it, capify your working rails directory and then replace /config/deploy.rb with the code below:

set :user, '' #dreamhost username goes here
set :application, "" #dreamhost domain name goes here 
set :repository, "" #path to your svn repo 
set :scm_username, "" #svn username 

# =============================================================================
# You shouldn't have to modify the rest of these
# =============================================================================

role :web, application
role :app, application
role :db,  application, :primary => true

set :deploy_to, "/home/#{user}/#{application}" 
# set :svn, "/path/to/svn"       # defaults to searching the PATH
set :use_sudo, false
# set :restart_via, :run
set(:scm_password) { Capistrano::CLI.password_prompt }

# saves space by only keeping last 3 when running cleanup
set :keep_releases, 3 

# issues svn export instead of checkout
set :checkout, "checkout" 

# keeps a local checkout of the repository on the server to get faster deployments
set :deploy_via, :remote_cache

ssh_options[:paranoid] = false

# =============================================================================
# OVERRIDE TASKS
# =============================================================================
namespace :deploy do

  desc "Restart Passenger" 
  task :restart, :roles => :app do
    run "touch #{current_path}/tmp/restart.txt" 
  end

  desc <<-DESC
    Deploy and run pending migrations. This will work similarly to the \
    `deploy' task, but will also run any pending migrations (via the \
    `deploy:migrate' task) prior to updating the symlink. Note that the \
    update in this case it is not atomic, and transactions are not used, \
    because migrations are not guaranteed to be reversible.
  DESC
  task :migrations do
    set :migrate_target, :latest
    update_code
    migrate
    symlink
    restart
  end

end