Many Internet global commercial services were originally initiated in the United States and later exported to other countries, continents, and cultures. By analyzing content and form characteristics of two leading portal sites - MSN and Yahoo! - on 33 and 23 (respectively) of their local country homepages in a comparative and longitudinal study over a period of six months, this study addresses two research questions: What differences, if any, are found among homepages of the same parent site located in different cultures (or targeted at audiences in different cultures)? What trends, if any, do those differences show over time? Although MSN is a U.S. brand, the analysis of its homepages reveals increasing cultural heterogeneity and localization of content and form. In contrast, Yahoo!'s homepages are found to be more similar to each other and to the "parent" American portal. A metric was developed to measure the distance between various websites in terms of form and content, along with a structured procedure to analyze and cluster groups of websites. The results suggest that the diversity of local homepages in MSN and Yahoo! follows the geographic and ethnographic scatter of their countries.