I'm currently using these for my signatures, together with quotes from http://themanwhofellasleep.com/gossip.html and http://www.aphorismsgalore.com/.

The code which sticks them into my sig is here:

It's basically equivalent to this (but a lot nicer, and doesn't do a download every time):

while 1:import urllib,re,time,textwrap,random;k=random.choice;time.sleep(5);u=\
"http://themanwhofellasleep.com/gossip"+k(("","2"))+".html";b='\nTom\n-- \n"'+\
textwrap.fill(" ".join(k(re.findall(r"(?:[1-9]|10)\.\s*([^<]*?)\s*<",urllib.
urlopen(u).read())).split()))+'"\n  -- '+u;file(".signature","w").write(b)

You'll note that the mechanism (sleep for 5 seconds, spit out the next one) is incredibly crude, but seems to work. A better version would atomically symlink the new version into place.