Use cookie to tie in conversations.

static/chat.js

@@ -2,15 +2,26 @@ jQuery(document).ready( function ( $ ) {
 	var $body = $("#body"),
 	    $send = $("#send"),
 	    $mesg = $("#messages");
-
+
+	var conversation = document.cookie;
+	if( conversation.length == 0 ) {
+		conversation = navigator.appVersion + Math.random() + new Date();
+		conversation = conversation.replace( /\W+/g, '' );
+		document.cookie = "conversation=" + escape( conversation ) + "; path=/";
+	}
+	else {
+		conversation = conversation.split( '=' );
+		conversation = conversation[1];
+	}
+
 	$send.click( function () {
 		var val = $body.val().replace( /^\s+|\s+$/g, '' );
 		if( val.length <= 0 ) { return; }
 		$body.val('');
 		$mesg.append( $('<div/>').addClass('me').text(val) );
 		$.get(
 			'/chat.txt',
-			{ conversation: 'lol', body: val }
+			{ conversation: conversation, body: val }
 		).success( function ( data ) {
 			$mesg.append( $('<div/>').addClass('don').text(data) );
 		} ).error( function ( xhr ) {