A trust metric is a technique for predicting how much a user of a social network might trust another user. This is especially beneficial in situations where most users are unknown to each other such as online communities. We think the recent tumultuous evolution of social networking demands for a collective research effort. With this in mind we created Trustlet.org, a platform consisting of a wiki for open research on trust metrics. The goal of Trustlet is to collect and distribute trust network datasets and trust metrics code as free software, in order to facilitate the comparison of different trust metrics algorithms and a more coherent progress in this field. At present we made available some social network datasets and code for some trust metrics. In this paper we also report a first empirical evaluation of different trust metrics on the Advogato social network dataset. Key words: Trust Metrics, Social network analysis, Wiki, Advogato, Free software, Data acquisition, Science Commo...