Austin,
Thanks for the PM and for posting this idea in public for our members.
"I haven't done anything else, no SEO, link building, PPC, funny handshakes, nothing."
You didn't even bother to do any "funny handshakes"?
Betcha turned around 3 times then bowed to the Google Gods though, didntcha?
Seriously though. That sounds like a great way to monetize dormant domains.
Just think though if you put some energy into the sites and built up some revenue you could flip them if they are good domains.