Writing articles can be an enormous method that can be used to create links. There are now thousands of free article directories online, each of which will take your links and happily link back to you.
Article Marketer does a very good job of distributing your articles for those of you that have a small promotional budget. They send your article to thousands of sites, giving it a ton of exposure and generating a lot of links in the process.
Writing an article is quite simple. One of the best methods I’ve used to create easy articles is rewriting articles I’ve already used on my sites. It only takes about 10 minutes to do it that way, and the leverage you gain from all the links is remarkable.
Creating free tools is perhaps the most powerful link building technique in the known universe. One example would be creating myspace layouts. People use those freaking layouts like crazy, and you can embed a link in each one. People will click on the links to find your site, and then they will want to use the layout as well.
When a tool you made goes viral, it can result in a massive amount of links for your site. Other examples of tools that can be used to get links are WordPress themes, gadgets, and widgets that people can use on their sites and blogs.
An exceptional method that can be used as link bait is holding contests. I once ran a contest where I promised to give my income away to anyone who could guess it. They actually had to guess within a dollar.
Quite a few people took me up on the offer. In order to enter the contest, they needed to create a post on their site, linking back to mine using my anchor text, and the number they were using to guess.
Within about 1 week, 70 or eighty people had taken me up on the offer. It worked out great for me, and in reality none of the people guessed that close. As an offer of goodwill, I gave some money to the person that guessed the closest. I think it was like $60 or something. Truth be told, I didn’t really need to pay it but wanted to.
The moral of the story is that contests can be used to create massive amounts of links.