Where does OS X store the profile photo it takes when you first create an account?
The photo can be found in the /Library/Caches folder, if you haven't cleared this folder yet.
Otherwise, I recommend typing:

dscl . -read /Users/short_username JPEGPhoto | tail -1 | xxd -r -p > 
/PATH/TO/accountImage.jpg

on one line in a Terminal window, from Chealion's brilliant answer here. In the above example, a JPEG copy will be saved to /PATH/TO/accountImage.jpg.