Dan,
This would be a fairly simple customization, just a few lines of html and some CSS to accomplish it. Of course the exact code will be specific to your site, and you would have to find the correct template to place it in.
Html:
Code:
<div class="my_floating_button">
<a href="help.php?section=contactus">Need Help?</a>
</div>
CSS:
Code:
div.my_floating_button {
position: fixed;
top: 80%;
}
div.my_floating_button a {
min-width: 120px;
min-height: 40px;
display: block;
background: #808080;
text-align: center;
line-height: 40px;
}
div.my_floating_button a:link,
div.my_floating_button a:active,
div.my_floating_button a:hover,
div.my_floating_button a:visited {
color: #fff;
}
I have not tested any of the above, just a starting point.