I am using one of these at the moment, small (a bit too small IMO) and fits easily in the pocket runs ICS.
http://www.techradar.com/reviews/phones/mobile-phones/sony-ericsson-xperia-mini-pro-1009076/review
http://www.techradar.com/reviews/phones/mobile-phones/sony-ericsson-xperia-mini-pro-1009076/review