Yes, tsuwm, that is one site I found by Google-ing :
"Kilroy Was Here"+cartoon
There are a whole bunch more, all with variations on the origin of the phrase.
I lean heavily on the version told me by my Dad and in Osgood's book. I have a vague memory of seeing a story about the real Kilroy in The Quincy Ledger, the paper of record in Quincy, Mass.