[Aetae]

<input name="test" type="text" id="test"/>
<script>
(function(){
var input = document.getElementById('test'),
    a = document.createElement('a');

a.target = '_blank';
a.appendChild(document.createTextNode(a.href = input.value));

input.parentNode.insertBefore(a,input.nextSibling);
input.oninput = function(){ a.firstChild.data = a.href = input.value};
}())
</script>