Proceedings of the Workshop on the Practical Use of Recommender Systems, Algorithms and Technologies (PRSAT 2010) held at the 4 th ACM Conference on Recommender Systems (RecSys 2010) 30 September 2010 Barcelona, Spain Jérôme Picault 1 , Dimitre Kostadinov 1 , Pablo Castells 2 , Alejandro Jaimes 3 1 Bell Labs, Alcatel-Lucent, France 2 Universidad Autónoma de Madrid, Spain 3 Yahoo! Research, Spain