gistfile1.rb

# Find all records tagged with a +'tag'+ or ['tag one', 'tag two']
# Pass either String for single tag or Array for multiple tags
def find_all_tagged_with(tag_or_tags)
  case tag_or_tags
  when Array
    all(:include => ['tags', 'taggings']).select { |record| tag_or_tags.all? { |tag| record.tags.map(&:name).include?(tag) } }
  when String
    all(:include => ['tags', 'taggings']).select { |record| record.tags.map(&:name).include?(tag_or_tags)  }
  end
end