I think these things rely very heavily on the angle and expression of your face. It will match you to someone with only a passing resemblance, but sitting at the same angle to the camera.
My son was identified as a mix between Jennifer connolly (he has long hair and straight eyebrows) and Michael moore (same glasses), and my daughter as kirsten dunst (same sweet smile) and Philip K Dick (not sure why - she doesn't have a beard or wrinkles).
ETA finally had the chance to go on the computer again and found it
http://www.myheritage.com/FP/Company/tryFaceRecognition.php?s=1&u=g0&lang=EN
You might like to try it - it's funny.