Hey Everyone,
Just thought I'd put it for the record, in case anyone else comes
along looking for this same thing, that I've found what seems to be
just the solution I was looking for!
http://web-graphics.com/mtarchive/001717.php
It's a pretty comic book-style dialog balloon (though upside-down! Do
Italian comics do it that way?? No matter, easy fix in GIMP or
Inkscape, I'm sure) and what's more, the code is simple enough that a
n00b like me can hack for my own purposes!
Indeed, there's even a very helpful -- structured, thorough, and n00b-
friendly -- explanation of how it works and how to use it.
Wow, the internet is so cool...wish the offline world worked the same
way! ^_^