Well, now you can
http://www.faceofthefuture.org.uk/
Here's what I and my flatmate look like as babies, children, old men, West Asians, East Asians, Afro Caribbeans and Old East Asians (for that one we took the picture of us as adults and uploaded them and applied the East Asian setting) - provides some very interesting and IMO realistic results! There are lots of other options too but we felt these were the most realistic/entertaining ones so I've just saved them, it's worth a look!