Hi Grollaz, I use floatbox which is a lightbox clone. I can click on an image/icon in my tour and it will open a any content within the floatbox.

You can see it in action here - just click on the Google map icon

Here is the script I use.

Place in your tour.html in the head section:

<link type="text/css" rel="stylesheet" href="http://www.YourDomain.com/floatbox5.7/floatbox.css" />
<script type="text/javascript" src="http://www.YourDomain.com/floatbox5.7/floatbox.js"></script>
<script type="text/javascript" src="http://www.YourDomain.com/floatbox5.7/options.js"></script>

<script>
function lightboxme(url, loptions) {

fb.start(url,loptions);

}

function rescroll() {
$('html').css({overflow:'auto'});
}

function lightbox_noscroll(url, loptions) {

$('html').css({overflow:'hidden'});
fb.start(url+'&'+$('#Form2').serialize(),loptions);

}
function resizefb() {

fb.resize();

}

//this one is to check if it´s not working that the call is being made to the right place

function checkcall(){

alert('got it!');

}
</script>

in xml this sets up the clickable image and associated target link

<!-- set optional skin logo url -->
<layer name="skin_logo" url="YourImage.jpg" scale="1.00" align="lefttop" onclick="js(lightboxme('http://www.YourTargetURL.com','type:video width:1050 height:710 sameBox:true'));" />


Floatbox is not free but you can try it for free no problem. I am sure there are other similar lightbox options out there for free and you just need to make the js call to it.

Hope it helps