acts_as_taggable_on: Match records tagged with all, any or none of the given tags

The tagged_with Show archive.org snapshot scope comes with many awesome options to modify your search:

User.tagged_with("awesome", "cool")                     # Users that are tagged with awesome and cool
User.tagged_with("awesome", "cool", :exclude => true)   # Users that are not tagged with awesome or cool
User.tagged_with("awesome", "cool", :any => true)       # Users that are tagged with awesome or cool
User.tagged_with("awesome", "cool", :match_all => true) # Users that are tagged with just awesome and cool
User.tagged_with("awesome", "cool", :owned_by => foo )  # Users that are tagged with just awesome and cool by 'foo'
Henning Koch Over 12 years ago