Is there a better way?

gistfile1.rb

class Array
  def to_hash(&block)
     Hash[*self.collect { |v|
       block.call(v).flatten
     }.flatten]
   end
end

# so that ["foobar", "barfoo"].to_hash{|i| [i.upcase, i.downcase] }
# yields {"FOOBAR"=>"foobar", "BARFOO"=>"barfoo"}
# to create a hash with keys and values coming from invocations of a method on an array element