Based on a discussion on comp.lang.python, I stole an idea from Chris Angelico. His D&D game has a parrot that listens to the chatter of the participants. You can ask Polly for a password and it will spit out an XKCD 936 password from the words it has seen.
I don't play D&D, but I get a ton of mail from public mailing lists and Internet forums, so I figured I could use that stream of messages as a word set. In deference to Chris, I named it Polly. Polly is written in Python and uses imaplib to monitor an IMAP folder for messages. It seems stable enough at this point that mentioning it outside of other threads on comp.lang.python seems useful. I have no official release, just a Github repository:
Feel free to fork it and play around. I've never used imaplib for anything, and figure that code code could use a bit of help.