Purpose: This paper aims to survey the web sites of the academic libraries of the Association of Research Libraries (USA) regarding the adoption of Web 2.0 technologies. Design/methodology/approach: The websites of 100 member academic libraries of the Association of Research Libraries (USA) were surveyed. Findings: All libraries were found to be using various tools of Web 2.0. Blogs, microblogs, RSS, instant messaging, social networking sites, mashups, podcasts, and vodcasts were widely adopted, while wikis, photo sharing, presentation sharing, virtual worlds, customized webpage and vertical search engines were used less. Libraries were using these tools for sharing news, marketing their services, providing information literacy instruction, providing information about print and digital resources, and soliciting feedback of users. Originality/value: The paper is useful for future planning of Web 2.0 use in academic libraries. (Contains 7 tables and 2 figures.)