Well, I poked around and figured it out. Thought I'd post what I did just in case anyone else comes looking for a similar answer in the future.
1. In inc/html.php, I edited function html_backlinks, commenting out this bit
print p_locale_xhtml('backlinks');
and putting below it,
echo "Pages linking here:";
2. in lib/tpl/default/main.php, I put, within the "stylehead" class DIV, another DIV calling the html_backlinks function, which I floated right and coloured the same as the "breadcrumbs" DIV. I suppose it could also be appended to "breadcrumbs" content and styled as a horizontal list, but I didn't feel like mucking around with the backlinks function beyond that, and like that it doesn't push the main content further down the page.
(Edited to add: Just realized, if the list made with this method gets long, it pushes the page editing window down.)