Culture is one of the classic and most widely studied topics in the field of technology. People of different cultural backgrounds interpret, consume, and disseminate technology differently. One conspicuous aspect of culture is communication. The expression, conversational patterns, and contextual nuances of different languages make communication a distinct cultural experience. Culture influences how communication functions between different people in different social contexts. It is also an underlying feature of encoded messages; a knowledge of the sender’s culture helps to discern his or her intention. Communication technology is also susceptible to the influence of culture. The mobile and social aspects of technology add another dimension to the communication process. Twitter, a leading social medium run on a mobile communication device, is a good example. This empirical study examines the use of Twitter in users with two distinctly different cultural ideologies: individualism (characteristic of the U.S.A.) and collectivism (common in Korea). Participants in both countries took part in a four-man group decision-making experiment. The groups were given decision tasks to complete within a timed period. The study yielded the following results: 1) the Korean participants tweeted significantly more often than the American participants; 2) the Korean participants initiated significantly more new tweets than the American participants; 3) the Korean participants sent significantly more friendly tweets than the American participants; 4) the American participants expressed disagreement significantly more often than the Korean participants; and 5) the Korean participants exhibited a significantly higher level of group cohesiveness than the American participants. These results shed light on the cultural applications of this new, emerging technology which is becoming essential to personal and business information sharing and communication of people of different cultures all over the world. Data analysis, discussion, and implications are provided.