Article marketing for sure. Blogfarms work great too, but for long tails not even really worth the risk. Use article post robot (haven't been able to find a free alternative that actually works properly), AMA, and UAW.
Really that is kind of overkill. One run with APR should take a long tail easy. (just rotate anchor text) If the keyword term is more competitive do the following.
Lets say you wanted to promote blackhatworld.
Rewrite an article three times. I use Unique article wizard.
Use APR to send out a spun article to blackhatworld.com
Register blackhatworldonline.com
Register blackhatonline.com
Send all the UAW backlinks to blackhatworldonline.com
Send all the AMA backlinks to blackhatonline.com
Link blackhatonline and blackhatworldonline to your main site blackhatworld. If you still can't rank just repeat the process by building more feeder sites. This works for very competitive terms as well. Check out the guy ranking third for vacuum cleaners. He just started up a few hundred blogs about vacuum cleaners and linked them all back to his main site vacuum wizard.
Feedshark is a great free resource as well for submitting your RSS feeds.
P.S. I don't even waste my time with 2.0. Pointless really. If a site actually works for backlinks google either destroys the authority or the site goes nofollow. (i.e. Digg)