Allows you to use render :new, :alert => 'You messed up' just like you can use redirect_to thang, :notice => 'You made thang successfully'.
Works with :notice, :alert and :flash => {:message => 'Sup foo'} just like redirect_to. With rendering it sets flash.now instead of flash.
Inspired after googling for this feature, it was written entirely by the mysterious P.B.F. and packaged into a gem by me. See: http://bit.ly/flash_render