Dear Colleagues, This is to announce that registration for the 5th Les Houches Workshop, Physics at TeV Colliders, is now open. The meeting in les Houches in the French Alps, between June 11th and June 29th 2007, will be the central point of this year-long Workshop. Participation in the Workshop is open to all. However, due to space limitation at Les Houches, attendance at the meeting is limited to 70 participants at any given point. We have also set up a forum and a wiki page to allow a more effective collaboration between participants throughout the duration of the Workshop. For more information and to register, please consult the Workshop page http://lappweb.in2p3.fr/conferences/LesHouches/Houches2007/ Short descriptions of the format, aims and objectives of PhysTeV07: The aim of this Workshop is to bring together theorists and experimentalists working on the phenomenology of the upcoming TeV colliders. The emphasis will be on physics at the LHC, particularly on progress in new techniques for the simulation of Standard Model processes and on the latest developments concerning new mechanisms of electroweak symmetry breaking and the associated New Physics. Issues ranging from jets and SM candles to Higgs and BSM will be discussed and tools covering these aspects will be critically reviewed and compared. Three Working Groups have been set up to cover these different aspects of physics at the LHC. The meeting in Les Houches is the central event of this year-long Workshop. Dirk Zerwas for the local committee ps: We apologize if you are receiving this message more than once