Orac on Respectful Insolence adds a cracker to his series taking on the Mercury-in-Vaccines-is-causing-Autism crowd.
Some years ago I was for a while concerned about the possibility that the mercury compound thimerosal that is used as a preservative in vaccines might have had something to do with my kids ending up with Autistic Spectrum Disorders (the togster has High Functioning Autism that was initially diagnosed as Asperger's Syndrome, the tigling has PDDNOS - Pervasive Developmental Disorder Not Otherwise Specified: people pick up that the togster has social skills difficulties easily while he fidgets and daydreams in the middle of a conversation, while the tigling's challenges are not so immediately obvious).
But the more I read the more I realised that the claimed connections just didn't have the evidence to back them up, and all the later studies that were done showed to anyone with a decent basic grounding in statistics that the claims of a connection were disproved. Orac does a thorough job in his many archived posts debunking the Mercury-in-Vaccines=Autism claim; that this post does a nice takedown of the self-anointed all-round 'expert' and bundle of trust-funded smug that is "Christian Libertarian" pundit Vox Day is a bonus.
A good lay-person site by a sibling on Autism and Asperger's: Weird Not Stupid