Well, my webhost was out for most the day and all my sites were down. Fortunately, I am finally back up. There error messages were all saying that the disk on the host was full, and all database connections were consumed.
So I am left wondering it it was a problem with my code gone wild, if it was a simple hardware failure, or if another site on the web host having problems. My logs did not show unusual activity. There were several malformed bots on my sites today. Days like this make me wish I had access to the server.