Lee Odden at the Online Marketing Blog has an interesting look at the comparison of linkbaiting and Digg-baiting.
Linkbait: Focuses on creating unique, useful and provocative content that people respond to by linking to it and sharing with others.
Digg bait: Focuses specifically on the interests of social communities and what they respond to. With Digg bait, the power is not in the usefulness and value of the content, but the title and description of the news item, sometimes bordering on the sensational.
Link, Linkbait, Digg, Digg Bait, Article