Ah well, on a roll and I feel like sharing...
Because multimedia files like Flash, Quicktime, etc. rely on EMBED tags for certain browsers, it can create problems for authoring XHTML-compliant pages for this content.
The Flash Satay method was a brilliant start to get the ball rolling, except that on IE5 and 5.5 it would lead to an unexpected visual glitch whereby an empty TEXTAREA box would appear.
I stumbled across
http://realdev1.realise.com/rossa/re...quicktime.html when I was researching a client's site to embed both QT and WMP files. Using a combination of CSS and clever embedding, you can produce results that are the closest I've found to being pure and compliant.
There is a couple of issues (but as a web developer, when have there never been?) - for some browsers you need CSS support to correctly 'hide' alternative content, and some older browsers will choke.
But the benefits are immediately usable, and you can also use this method to stuff some extra content (= keywords!) into your fallback content as a bonus.
Hope this helps someone.