Re: Promoting a Social Network. Discuss.
SEO… submit your site to Google, Yahoo and various web directories, write good blog articles relevant to your niche and link to your interior pages. Submit your articles to social sites like Digg and Mixx… pray that it becomes popular 
SEO isn’t an exact science… but it helps.
Like DJPaul said, also network with others with similar interests (Facebook, Twitter, etc.). Write guest posts on their site (if they have one), etc.
