It would be ideal if people could just view panoramas and photosynths directly in Facebook. There used to be a third party Facebook app called MySynths that did this, but it's since gone offline. Back when they were still up and running, though, I posted an aerial synth of my old boarding school in Papua New Guinea and heaps of people liked it and posted comments.
A couple of years ago when I visited my grandparents in Florida and visited with some old schoolmates while I was there. I shot a panorama of some of them playing basketball while others watched. I stitched it with ICE on Windows and uploaded a flat version to Facebook with a link to the full resolution wraparound pano on Photosynth.net in the caption and got some clicks that way.
That way you can give people a taste test and if they want more, they can get it. It also gives you the ability to tag people in the Facebook version where appropriate which draws in attention and shares.