ruby script/plugin install http://wonsys.googlecode.com/svn/plugins/acts_as_fulltextable

Add the following code to the model that should be included in searches:

acts_as_fulltextable :fields, :to, :include, :in, :index

Create the migration:

script/generate fulltext_rows model1 model2 model3 ...

Then execute it:

rake db:migrate

You can either run a search on a single model:

Model.find_fulltext('query to run', :limit => 10, :offset => 0)

Or you can run it on more models at once:

FulltextRow.search('query to run', :only => [:only, :this, :models], :limit => 10, :offset => 0)

Warning

Should you add acts_as_fulltextable to a new model after the initial migration was run,
you should execute the following piece of code (a migration or script/console are both fine):

NewModel.find(:all).each {|i| i.create_fulltext_record}

It will add all of the model's instances to the index.

There is currently no advanced documentation for this plugin.