Mobile SEO How to do SEO for mobile phones

The best way to do SEO for mobile phones is to create a mobile version of the website. Google has created some guidelines which can help you rank better on mobiles. Google uses a different metric when comparing  your mobile site, it has a different algo all together for mobile search results. Hence ranking in serps can be easy even for tough keywords
http://googlewebmastercentral.blogspot.in/2012/06/recommendations-for-building-smartphone.html

Mix your links do follow links you should mix

With the recent changes in the google algorithm it is important that you mix your links. Don't just aim for profile, and comment links. You should also try to get backlinks from article sites, directories. Articles sites are ranked well because they have more content and google prefers content.
Social bookmarking sites don't do well now a days still a few of them are alive and will get themselves indexed fast. So if you put content on them, they will get indexed and traffic will come from Social Bookmarking sites.