Baekdal.com has a post up in relation to viral video marketing, but I think even articles and blog posts can be somewhat viral, and thus fall under many of the same rules.
1: Make people feel something
2: Do something unexpected.
3: Do not try to make advertisements (that sucks)
4: Make sequels
5: Allow Sharing, downloading and embedding
6: Connect with comments
7: Never restrict access!
As you can see, I only really had to remove one thing from the list, as it didn’t fit with blogs. The rest I totally agree with. I think the biggest one though is doing something unexpected, at least if you want it to go viral. It doesn’t have to be crazy, though that is how many of them seem to end being. Writing something different, thought provoking, or interesting can be difficult, but when it spreads to the front page of many social news sites, I am sure a big smile will stretch across your face. At least until your hosting server goes down from the flood of traffic.