Of all the legacies of the era of the sixties, three colorful, not to say garrulous, "personalities" that emerged from the early days of artificial intelligence research are worth mentioning:  
ELIZA, the Rogerian psychotherapist;  
PARRY, the paranoid; and (as part of a younger generation)  
RACTER, the "artificially insane" raconteur.  
All three of these "characters" are natural language processing systems that can "converse" with human beings (or with one another) in English. That is, when presented with sentences in English as their input, they produce other grammatical sentences as their output, which sometimes manages to give the flavor of a conversation.  
I'm tired of seeing the 'ooh, look at this conversation with X bot online', so here's the definitive link: one classic bot converses with another.  
Also, Racter's poetry at the end should be read with a grain of salt: this link says that most of it could not have been written by the program!
Great Post, Hornpipe!
leyman: That brings back a vivid memory from when i was 15 years old in 1975. One of our neighbors was a GM R&D dude and i got to go to an open house at the GM Tech Center in Warren, Michigan. I remember sitting in front of one of those old teletype deals typing in questions and answers with my neighbor and me waiting anxiously for the clickity-clackity output of the computer on the terminal, digit by digit. It was all very interesting and i got to keep the printout. Didn't get me very interested in IT/AI at the time, (i had other pursuits on my burgeoning young mind) but it *was* way cool!  
A couple of years later i was in college loading Fortran-coded 3X6 cards into the clackity-clack card readers awaiting the compiling of my source codes for further execution... man, am i old...!  
Interesting that GM had it installed on their mainframe. But at the time GM had $$$ to burn...  
Makes me wonder if the printout is hiding away somewhere in my very very old files i haven't gone through in years. I always have been a bit of a packrat... would be quite a find, maybe...