accessing validates_... , :message => 'something'

I do believe your supposed to pass in the i-var, not a string or symbol:

<%= error_messages_for @user %>

You can also loop through the error messages yourself this way:

@user.errors.each_full_messages
do |message| stuff; end

Jason

String. At least the source handles strings; maybe symbols too, I'm a
bit fuzzy on that. Note line 105.

# File vendor/rails/actionpack/lib/action_view/helpers/active_record_helper.rb,
line 103
103: def error_messages_for(object_name, options = {})
104: options = options.symbolize_keys
105: object = instance_variable_get("@#{object_name}")