Everyone thought that the GS2 was the thinnest smartphone, but there is actually one thinner than the Galaxy S II, it is the MEDIAS N-04C. You can check it out HERE. It is 7.7mm thick and the GS2 is 8.49mm thick. The MEDIAS N-04C runs FroYo and has NFC, it is an okay little phone. It is only available in Japan, so I guess the GS2 will be the thinnest smartphone in the US for now until Apple tries to out do Samsung.