Alas, there is one more problem before we can use the OBJECT tag. Paranoid admins (and who can blame them?) have taken to stripping out the OBJECT tag (at least when it specifies the data="" attribute). At work, I am unable to see the examples, nor the right side menu bar in Tantek's log. Has anyone else observed this? I don't know how common it is, but I fear the worst.
If you use text as the lowest nested element (as you should), eg:
<object type="video/mpeg" data="sunset.mpg">
<object type="image/jpeg" data="sunset.jpg"> Sunset in Hawaii
</object>
</object>
Then it shouldn't matter that a sysadmin strips the Object tag away as you would still get the fallback text which could include a link to download the data. So I really don't think stripping away the Object tag violates the spirit in which the Object tag was devised to be used.
Internet Explorer's inability to properly nest Objects has always been the major problem.