http://en.wikipedia.org/wiki/Super-Earth, http://solstation.com/planets/super-earths.htm
There is a lot of speculation of other living worlds.
http://news.ca.msn.com/top-stories/2-super-earths-found-in-habitable-zone-of-star
http://www.latimes.com/news/science/sciencenow/la-sci-sn-exoplanet-liquid-water-20130418,0,4179317.story