I just found a cool blog post from Daniel Fischer regarding the public relations and the web site marketing.
What Daniel very correctly sais is that you have to – at least try – to contact with other webmasters of your niche and ask them for links or help regarding your site.
This thing is not working so well – I mean that you wont get so many links this way – but even the small number of links that you’ll get can help with traffic and SEO, plus those people may stay in touch with you or your site.
Daniel points google to help you find sites of your niche, but I’ll also point to stumbleupon which has a tag browsing feauture. This way you can enter the tag that best describes your site, and find top rated sites in your niche.
The results are very good, as this way you can both socialize your business and get some inbound links to your site.