People here have advised you to go get a memory card recovery utility. TRY THAT. you do realize that PCs have not really formatted devices like your thinking for a long time now. They don’t do low level formatting anymore because drives have gotten so huge it would take days. Formatting now merely erases the file system and gets you ready quickly. The files are still there but the directory is erased so the device thinks it’s empty (over simplifying). So these image recovery utilities scan the surface of the drive and look for “files”.
Your files might still be there if you haven’t recorded new imaged or videos.
Follow up: Tried a recovery program. It showed a few files, but none of those from the Phantom... so, weather was still nice, the card had already been reformatted, so I took the ride, and this time brought my laptop along to transfer files immediately so I could 1) see that they worked properly, and 2) back them up immediately. All went fine.
In fairness, I should say that in the past few flights before the problem, it was warning me that I might want to reformat the card... and I ignored it. So, I guess the blame is on me. Sort of like a check engine light, I guess.
Also, whether or not it was a "real" formatting or not, the format took probably 10 minutes to do, so I wonder if it was more than just erasing files. Don't know, really.
But anyway, I got some good stuff, made friends with a cop (I was in the parking lot of a closed business), and all is well. Cop was very interested in the 'copter. Apparently he's been thinking about getting one.
As always, thanks for all the quick replies.