My nephew has done it for members of our family past... It is cool but weird at the same time. Smiling, blinking and moving is strange when it is your dead grandad or something. Or your mom as a baby.
I've done it through My Heritage with mixed results. The software didn't recognize the faces on some of the smaller images I tried to upload, and it kind of tried to "prettify" my Italian Nona, who was a tough looking, swarthy, not traditionally attractive woman, so the animated version, which made her look lighter skinned and less heavy, didn't really look like her. Surprisingly, the one I had the best results with was a charcoal drawing of my great grandfather - not a photo at all.
One piece of advice - don't try to animate a picture of someone you knew looking the way that they did when you knew them. It's a bit less creepy if you see them as they looked before you knew them.
Oh, and I wasn't thrilled with the results of the free trial, so I didn't take out a subscription, and a week or so later, I got an email letting me animate 5 more photos.
Did anybody hear about the new My Heritage feature called Live Story? This feature allows you to create a digitally animated photo using text and a voice to allow your ancestor to tell their story.