To facilitate the execution of short ( 8 h) programmes, we propose ``service observing'' for some easy to observe (e.g. short, single source) programmes with only one set of tunings. Observations are made by the local staff. This is a passive way of observing, no direct interaction with the telescope through OBS being possible. For this type of observation, we request an acknowledgement of the IRAM staff member's help in the forthcoming publication. Please, if you are interested by this mode of observing, specify it as a ``special requirement'' in the proposal form (IRAM will decide which proposals will actually go to that mode).