Thanks! Your response marks one of the most complete I've seen, much less enjoyed direct use of.

Thanks again,

Grar

One approach, define formatted versions of your attributes that need indicative defaults, i.e. in your model which contains an attributed named 'field_needing_hint',  assume you want to indicate a dollar amount be entered:

def cvt_dollar(str)
  str.gsub!(/[^0-9.]/,'') 
end    
def fmt_dollar(fld) 
  "$ " + fld.to_s.reverse.gsub(/...(?=.)/,'\&,').reverse
end
def  formatted_field_needing_hint
  fmt_dollar(field_needing_hint) 
end
def formatted_field_needing_hint=(str)
  self.field_needing_hint = cvt_dollar(str)
end

I also use an onblur event handler on the client side to enforce a proper dollar format, i.e.:

formatDollar = function(num) {
  num = num.toString().replace(/\$|\,/g,'');
  if(isNaN(num))
    num = "0";
  sign = (num == (num = Math.abs(num)));
  num = Math.floor(num*100+0.50000000001);
  cents = num%100;
  num = Math.floor(num/100).toString();
  if(cents<10)
    cents = "0" + cents;
  for (var i = 0; i < Math.floor((num.length-(1+i))/3); i++)
    num = num.substring(0,num.length-(4*i+3))+','+
      num.substring(num.length-(4*i+3));
  return (((sign)?'':'-') + '$ ' + num );
}

That's just some random JavaScript formatting code, use whatever you like,  then in my views:

form_for @thing  do |f|
    text_field :formatted_field_needing_hint , :onblur=>"this.value=formatDollar(this.value);"
end

So if field_needing_hint is nil or contains "0",  the user will be prompted with "$ 0" as the default value.

I'd like to very strongly hint at the acceptable format of some of my textfields by 'prepopulating' them with indicative characters when the user enters the fields. So, with some effort I could devise javascripts that populate textfields with '%' or currency signs or separate digits with commas. Yet, these are all things that Rails' NumberHelper will do on the server-side. Ideally, I could just call those utilities on the client-side. Any suggestions on how to do this or otherwise accomplish my task using existing resources?

Thanks,

Grar