You can now embed links to Soundcloud and Youtube. They look like this:
and generate this:
I'll try to modify the theme sometime to stop Soundcloud making a scrollbar in some browsers (Opera, that is).
The youtube tag supports any of the following three formats:
Note in particular that https: is not supported at present.
(NB - this has changed - see next post)
Be aware that the soundcloud object doesn't show on Apple devices (it's currently Flash, though an HTML5 interface is available, which I'll look into using), and Tapatalk can't cope with either of these tags.