Welcome malinator! You'll find this to be one of the friendliest forums around -- I've learned to assume the best instead of the worst, but it's easy to assume the worst when you've hung around some other places where everyone seems cranky. :)
I have been really impressed with Random Words by Ozh. (http://frenchfragfactory.net/ozh/my-projects/wordpress-plugin-random-words/)
Extremely simple to use -- you can set up multiple lists of words if you want, but you can just set up one. You just put all the things you want to randomize in one textarea in your admin, and then put a tag in your sidebar, or wherever, like this:
* In posts:
* In PHP:
<?php wp_ozh_randomwords('name_of_the_list') ?>
The list of things to randomize can be just about anything -- HTML, plain text, whatever. I need to use lots of different random things in lots of different places, so it's great for that. But if I only needed randomness in one place, I'd still pick it for it's absolute simplicity.
I did tweak the Hello Dolly plugin for admin -- pasted in my own fav song. :) But I haven't tried making it work in the rest of the site, since Random Words is so simple.