This report presents findings from a two-year investigation of the ways in which Web 2.0 tools and social networking technologies are being used to support teaching and learning in classrooms across the United States. With funding from Intel[R], the Education Development Center's Center for Children and Technology (EDC/CCT) interviewed or visited over 30 educators in 22 different schools throughout the country as they employed these tools in their classrooms in innovative ways. The authors also spoke with and observed a number of students in these schools. Over the two years of their research, the sample of teachers was drawn from the Intel[R] Teach Essentials course and the network of master teachers and training agencies that has grown up around that program. Through this network of educators, the authors sent out a request for volunteers to teachers that are experimenting with Web 2.0 technologies in their classrooms. During the first year they recruited 12 individual teachers, but for the second year they targeted districts with larger groups of teachers experimenting with Web 2.0 and were able to reach 27 educators across three districts. This report is divided into two sections: (1) a summary of some of the most frequent Web 2.0 applications they encountered and (2) a discussion of different themes and issues concerning the use of Web 2.0 tools in classrooms that emerged from all the interviews and visits. Appended are: (1) Tools that create or support a virtual learning environment; (2) Tools that support communication and cultivate relationships; (3) Resources to support teaching and learning; and (4) Tools enabling students to create artifacts representing what they are learning. A bibliography is included. (Contains 4 tables and 1 footnote.)