Jim, one of senior DP member has written about Link baiting here.. http://www.jimwestergren.com/link-bait/ its really good article to go through check 'em
Well any good article can get links, if it's unique. But link-bait is really, the way I understand it, the type of article, or gadget, or picture or whatever that people will really, really, really like - and therefore easily link to.
It's like catching fish You through the bait out and hope some webmasters will bite with a few links. Check out textlinkads to what they offer for this service... Quite expensive though. Link Bait
Here's an example of my idea of link bait: http://www.vegetablecruelty.com/2006/11/01/calling-out-animal-rights-activists/ Exactly what Subzero, kh7, and Dfischer said - it's whatever might motivate others to link back to you. It doesn't have to be something they like - it can be something they don't like also.
I guess just like anything, you need to get a bit of interest in your item to get it started is to go out and promote your Link bait url somewhat to get it started. So, If I wanted to use something like http://photoblog.shrinkpictures.com/index.php?showimage=231 as the bait, I just need to get a few people visiting the site, and hoping it goes viral?