There are numerous ways to promote yourself, your writings and your blog. Some are more ethical than others, but each writer has to answer only to himself in which ways he wants to promote his blog. You can spam fora, spam comments, litter your blog with digg buttons or spread your articles in any other way.
I always figured that writing guest articles is a nice way to mix crowds. As guest writer you get the chance to speak to a whole new audience, in return ones own readers will discover a new blog. And in the end, it's still always about the content, which is what matters the most. It came as no surprise that I jumped at the opportunity when it arose.
The article I have written for wpdfd is about the function of html, highlighting its neglected structural function and baring the problems of minimal html.
Interested? Follow the link to read my article on html, the foundation of the web.