ruby script/plugin install svn://code.spinbits.com/plugins/simply_searchable/trunk

In your PostsController add:

simply_searchable :fields => ['title', 'author_id', 'comments']

In your routes.rb add search method to your desired resource:

map.resources :posts, :collection => {:search => :get}

Generate the search results page that shows the post's title and body:

ruby script/generate simply_searchable Post title body

visit /posts/search and start passing your filters:

/posts/search?author_id=1				  # View posts from author 1
/posts/search?title="test"				  # View posts with the title 'test'
/posts/search?comments=1&author_id=3	  # View posts that has comment 1 and written by author 3
/posts/search?author_id[]=1&author_id[]=2 # View posts from both authors 1 and 2

There is currently no advanced documentation for this plugin.