twitter applications on blogs and other social bookmarking widgets are really helpful, it can spread the word out to everyone and promote our blog easily.
There are many seo techniques not tools for promotion of blogs/sites, the most important seo technique according to my experience is web 2.0 properties link wheel because it will give you powerful backlink as well as decent exposure.
social bookmarking is most effective for blog marketin and also u can use twitter but do it for targeted users who have interest in the same topic that ur blog is..
Make sure that you have enabled the RSS feed for your blog - this means your blog can be syndicated and picked up by other websites and users. You just have to tick the right box in your blogger account.