Someone

<textarea name="title" id="title" class="form-item"cols="30" rows="3"  onKeyDown="textCounter(this.form.title,this.form.remLen,250);" 
onKeyUp="textCounter(this.form.title,this.form.remLen,250);"></textarea>

<input readonly type=text name=remLen size=3 maxlength=3 value="250"> characters left

<SCRIPT LANGUAGE="JavaScript">
<!-- Begin
function textCounter(field, countfield, maxlimit) {
if (field.value.length > maxlimit) // if too long...trim it!
field.value = field.value.substring(0, maxlimit);
// otherwise, update 'characters left' counter
else
countfield.value = maxlimit - field.value.length;
}
// End -->
</SCRIPT>