I have read a useful article on 'Linkbaiting'. Though written in 2006, it is still interesting.
Do you know what 'Linkbaiting' means? 'Bait' is a worm placed on a hook for taking fish. And 'Link' is a link that you wish to get from other sites.
So linkbaiting is about hooking. Link bait is a feature within your website that somehow baits viewers to place links to it from other websites.
The above mentioned article by Darren Rowse is talking about 20 Linkbaiting Techniques: tools, quizzes, contests, humor, etc.
I personally like the technique named 'Lists'. Organize your info in a form of a list: first..., second..., third... There is something about a list that people latch onto and want to pass on to others (check out digg and delicious to see plenty of examples).
Learn good techniques for linkbaiting. It can be an extremely powerful form of marketing as it is viral in nature.