This will stop 'some' users:
<html>
<body onHelp="alert('Please Do Not Use The Keyboard.'); event.returnValue=false; return false;">
<script language="JavaScript">
<!--
document.oncontextmenu=new Function("event.returnValue=false; return false;"

document.onselectstart=new Function("event.returnValue=false; return false;"

document.onCopy=new Function("event.returnValue=false; return false;"

document.onPaste=new Function("event.returnValue=false; return false;"

document.ondragstart=new Function("event.returnValue=false; return false;"

document.onkeydown=new Function("alert('Please Do Not Use The Keyboard.'); event.returnValue=false; return false;"

document.onKeypress=new Function("alert('Please Do Not Use The Keyboard.'); event.returnValue=false; return false;"

document.onKeyup=new Function("alert('Please Do Not Use The Keyboard.'); event.returnValue=false; return false;"

document.onselect=new Function("event.returnValue=false; return false;"

document.ondragdrop=new Function("event.returnValue=false; return false;"

document.onmousedown=new Function("event.returnValue=false; return false;"
// -->
</script>
Press some keys . . .
</body>
</html>
hth,
Foxbox