After many issues with a prettyphoto plugin (mainly how things work with external content and also the results on iOS devices), I am looking into another plugin, Lightbox Plus Fancybox.

Here is just a normal image with Primary Lightbox Fancybox:

Ludo

Here is a Secondary Lightbox Fancybox (with iframe) with an external site:
Enjoy the Flavor

Here is a Secondary Lightbox with an external site, video from YT:
Ventura Co Coast time lapse test

Update:
lots and lots of searching and it really looks like there are not any (unless you pay or license, which I’m not in a position to do right now) overlay plugins that will work really well on iDevices.

So I did find one that seems to work ok, but not perfect. Right now I’m using Fancybox for WP.