I know that all of the books and what not say that teething tends to start somewhere between four and eight months, but I knew my boy would overachieve in that too. He started drooling a lot a week or two ago, and his lower gum looked and felt hard in the front. I knew it was coming. I didn't put it together though until this morning, when Diana pointed out one was starting to break through. That explains the cranky Simon, the weird sleeping and eating patterns (now that they were getting regular) and the strange gnawing on the bottle nipple.
They grow up so fast. :)