I figured out that you can use Clearspring's widget publishing platform to embed and share your panos.
Here's some preliminary samples / tests...
widget embedded... http://testsite.marlincreek.com/tests/34-pano/99-test-embed-widget
widget page on clearspring... http://www.clearspring.com/widgets/4934c2c0580b3706
different widget page on clearsping... http://www.clearspring.com/widgets/49397ad3dda6106d
That last one uses plugins for choosing the different panos to view.
I've posted them to my facebook wall without a problem... and have embedded them in the testsite... and emailed them (to myself : ) )... but haven't tried it out on every option.
The clearsping documentation says that this shouldn't work... but it is for now.
The embed works via javascript to dynamically create an iframe on the page... all content is served from original source server.
Graydon
Edited to update link after changing something on the test site.