(function(){
var data = { data: location.href }
jQuery.post('http://api.openkeyval.org/myownkey', data)
}())
And on each client you have a screen-sized iframe + an "update" button that triggers:
$.getJSON('http://api.openkeyval.org/myownkey', function(data){
iframe.src = data
})
You have to remember to use your local IP address, not localhost. I ended up making a small nodejs server so we could use websockets and drop the update button.