Implementing keyword arguments

I really want to add the ability to use keyword arguments in Rails.
What's the best way to implement this seemingly massive change?

  I can't figure out if I should add a layer (plugin, perhaps) where I
accept both style of arguments and pass them along in the preferred
format/order, or attempt patching the methods directly.

  Actually, I'm hoping I'm /way/ off base and there's some way to
abstract this.

  Lists just seem so wrong, and so non-Rails, to me.

  Doesn't password_field_tag(nil,nil, {:class => 'some_class', :id =>
'an_id'}) bother anyone else?

  Nil arguments? Ugh!

  I'd love to discuss this with anyone who's inerested.

Thanks,
John

P.S. Please let me know if this should be posted to a different list