If you have a look at some of the big social bookmarking sites one thing really stands out: lists are good linkbait. There are countless blog posts and articles that describe such things as the top ten ways to do brush your hair, or the five best movies in a particular genre.
Similarly, people are often interested in lists of websites that are useful. If you assemble one of these related to a particular category and then post it to your blog or site, then you're almost certain to get some backlinks to it eventually. They may be from social bookmarking sites, but they're more likely to come from online forums.
I just had an illustration of this recently. A list of Australian directories that I've accumulated and published on one of my sites has been linked to from an Australian forum.