S.B.
He could be getting his two year molars. Our three year old has always been a drooler. He still does it but it is getting much better. When he was a little over two it got REALLY bad, soaking collars and such, like you said. It even gave him a rash on his chest. My brother in law, the dental student found the culprit...two year molars. Once they broke through his drooling was MUCH better.