Recently I used aaron walls link harvester tool www.linkhounds.com/link-harvester/ to have a look at my main competitors backlinks. I googled my main term and used the top 10 results in link harvester.
It brought back a list of all backlinks to those sites, including .edu, .gov, .ac.uk etc, basically all the 'authority' links as well as your regular backlinks.
I figured, hey, if they can get links on .edu sites I might as well give it a go. I spent an hour or so finding contact info for these .edu pages, wrote a nice, personalised complementary email saying basically if you think my site is worth it please add my link.
Whorush: 1138 sites by this AdSense ID
Didn't think anything of this until today when I was checking my backlinks, who would have thought - 2 backlinks from different .edu's!
So, if you have an hour or 2 to spare its well worth a try and you may well be surprised with the results as i was!