Hi all.

If your Operacional System is Ubuntu and you are using Ruby on Rails 2.0.2 you can easily use it:

$ sudo apt-get install sqlite3

$ sudo gem install sqlite3-ruby

SQLite3 does not use authentication and needs only a pointer to the database file on database yml.

development:
  adapter: sqlite3
  database: db/development.sqlite3
  timeout: 5000
test:
  adapter: sqlite3
  database: db/test.sqlite3
  timeout: 5000
production:
  adapter: sqlite3
  database: db/production.sqlite3
  timeout: 5000

When you run "rake db:create:all" on your RAILS_ROOT it creates all 3 databases.

More information about other plataforms?

Here: http://wiki.rubyonrails.org/rails/pages/HowtoUseSQLite

See you.