Do you have MVS (Mark V. Shaney) in your list? MVS dates back to about
1985, and was probably the first of the "automated posters" on Usenet. It
would take postings from net.singles and generate new postings by combining
sentence fragments in almost-understandable ways, by using Markov Chain
techniques. (Note the similarity between Mark V. Shaney and Markov Chain.)
It was written up in the Mathematical Games section of Scientific American a
few years ago.
(see also the article "I Spent an Interesting Evening Recently with a Grain of Salt" by Penn Jillette (http://www.sincity.com/penn-n-teller/pcc/shaney.html) and "Thus Spake Shaney" (http://www.chunder.com/text/thusspakemvs.html))