Hey there, I've got a basic system running on StopTheSearch.com in the sidebar just below the twitter feed.

There's a few parts that need updating:

Custom CSS
------------
#quote-box-text div {
display: none;
}

and customize this sidebar code with your own tips/info:

In the Sidebar
<div id="quote-box-text">
<div>In one day, a slow dripping tap would fill a bathtub.</div>
<div>Fossil fuels were formed from the remains of ancient plants and animals</div>
<div>How many times can a piece of paper be recycled?  About 7 times.</div>
</div>

then finally in the footer

<script type="text/javascript" charset="utf-8">
$(function() {
var randomNum = Math.floor(Math.random()*3);
$('div#quote-box-text div:eq(' + randomNum + ')').css("display", "block");
});
</script>

This code certainly isn't perfect but it'll get you up and running quickly. One thing, in the footer you'll see *3... change that number based on how many lines you've got in the sidebar call. Yes, it would be better if this figured itself out itself but hey, I'll leave this as an exercise for our readers :)