Interesting button on an order form I saw: It deals with the issue of multiple clicks on a submission button by changing the name when the user first clicks on the button and ignoring additional clicks.

<script type='text/javascript'>
<!--
document.write("<INPUT TYPE='button' NAME='Submit' 
   VALUE='Submit Secure Order' onClick=\"if(this.value == 
   'Submit Secure Order') this.form.submit(); 
   this.value = 'Working...Please Wait.';\">");
// -->
</script>
<noscript>
<INPUT TYPE='submit' NAME='Submit' VALUE='Submit Secure Order'>
</noscript>