MIT's new Center for Graphene Devices and Systems (MIT-CG) has an ambitious plan - to produce a one-kilometer square sheet of graphene. They are currently starting to develop the basic science and technology - which is based on the printing press. The idea is to grow graphene in a roll to roll process. MIT hopes that if they manage to develop this technology they'll enable a whole new graphene industry.
Currently they've been able to grow small sheets only using this technology (a "few centimeters" in size). The largest graphene sheet made to date was 30" square (produced by Japanese and Korean researches in June 2010) - which was also made in a roll-to-roll printing process. There were reports of a 40" graphene sheet produced by Samsung in January 2011 but these reports weren't confirmed.