Here you go http://jsfiddle.net/Calou/9N9Tz/6/.
When the value of the s changes, just take this value and search for the
s with this value in the others
s and remove them.
$(".one").change(function(){
var val = this.value
if (val !== '') {
$(this).siblings().find('option[value=' + val + ']').remove()
}
})