This document summarizes research on social networks and relationships in virtual worlds. It finds that virtual world communities form and operate similarly to real-world communities, with people connecting based on shared interests, experiences, and reputation. Trust is important online as in offline communities and develops through factors like frequency of contact, similarity, and self-disclosure. The anonymity of online interactions gives way to pseudonymity, and reputation systems allow trust to be established. Social network analysis is used to map these relationships and identify influential individuals. Ethical considerations are important to maintain participant trust in research.