Building Link Popularity
If search engine optimization were as easy as making modifications to your site, everyone who put enough work into the process could be #1 on all of their search terms. Unfortunately, it’s not as simple as that. External factors, specifically other websites, come into play to determine your placement along with your page content and optimization.
Link popularity and relevance are the two key factors when it comes to other websites. Search engines read links pointing to your site, the pages that those links are found on, and the text associated with each link. If you have many links coming from popular, high PageRank sites that are relevant to your topic, you’ll enjoy a high placement, sometimes even if you don’t optimize for a particular keyword.
When it comes to increasing link popularity, you’ll want to start finding link sharers (i.e. website owners with which you can share a reciprocal link). It is also a good idea to sign guestbooks and comment on blogs. Include your page url in signatures in forums and emails. Essentially, spread your link around wherever you can. The more links coming to your site, the higher rank it will receive.
I recently came across two forum strings that may be of use for building link popularity, How to Find Thousands of Quality Backlinks and Link Building.