how do you change the currency to pounds or euros

hi guys great forum for ruby on rails
can anyone tell me how to change the currency to anything other than
$?

http://api.rubyonrails.org/classes/ActionView/Helpers/NumberHelper.html#M000520

Note the :unit key in the options hash. So:

number_to_currency(42.50, :unit => '!') => !42.50

~ j.