There are several questionnaires available online to test for Autistic spectrum disorders.
http://www.childbrain.com/pddassess.html
http://autism.com/atec/
This one is more ADD focused, but still useful information.
http://www.amenclinic.com/ac/addtests/brain_system_checklist.asp

One interesting thing is that Tommy scores significantly and I feel very confident in his Asperger’s diagnosis. Noah has some personality traits that are Autistic but he doesn’t even score as PDD. Will Noah’s traits remain consistent, become less evident or will he fall behind same age peers as he gets older and work his way onto the spectrum?