On June 24 there is a RFID sniffer workshop at ProtoSpace aka FabLab Utrecht. For more information and signing up look here.
On June 26, there will be another RFID sniffer workshop, this time at CabFabLab, The Hague, The Netherlands. This is the FabLab in the former Caballero cigarette factory.
(This workshop is rescheduled, and was previously announced for June 12)