Special topic: Pump Probe experiments with the new THz beamline at FLASH DESY is planning a major upgrade of the FLASH facility in 2009. In particular, the electron beam energy will be increased by an additional accelerator module to reach wavelengths near the carbon K-edge, and 3.9 GHz cavities will be installed in the injector affecting the properties of the FEL pulse such as pulse energy, duration and structure. In addition, new instruments will become available in the experimental area. The workshop will inform present and potential users about these developments and provide a forum for discussions about new research opportunities at FLASH as well as plans for further developments and extensions. The workshop will be useful for scientists who are planning to submit a proposal for experiments at FLASH starting after the shutdown in 2009. One day of the User Workshop will be dedicated to the recently completed THz beamline. This beamline is presently undergoing extensive commissioning and continuous development and is planned to be become a regular part of the FLASH user facility in the new proposal period starting after the 2009 shutdown. Promising ideas for future pump-probe experiments utilizing the new THz beamline will be discussed based on the first commissioning results and with the aim to prepare the beamline for the experiments. We invite all interested colleagues to participate in both parts of the workshop. For the special topic part on the new THz undulator beamline we invite you to submit abstracts for poster contributions or talks. Posters should have DIN A0 portrait format (0,90 m x 1,20 m (width and height)). The conference language will be English. The workshop fee for all participants including speakers will be 30€ and is to be paid in cash at the workshop registration desk. Participants are asked to arrange travelling and accommodation on their own. We strongly recommend you to book your accommodation as soon as possible. Deadline for registration and abstracts for the special topic: 22. August 2008.