As an SEO, I am always trying to find quality links. I've taken over SEO for companies that have been involved in link-farms.  I have taken over SEO for companies that have been involved in forum spamming, on unrelated forums to boot. I refuse to go down either of those roads.

How about this?

Run a promotion on Twitter, a good promotion.  Twitter is free, so you can splurge on the giveaway.  Create a good landing page for the links from Twitter.  Advertise the promotion on your website.  Run some pay per click before the promotion launches, so people can see the advertisement on your homepage.  Perhaps they might spread the word.  Perhaps they might even link to you.