Most real networks often evolve through time: changes of topology can occur if some nodes and/or edges appear and/or disappear, and even if the topology stays static, the types or weights of node and edges can also change. Mobile devices with wireless capabilities (mobile phones, laptops, etc.) are a typical example of evolving networks where nodes or users are spread around in the environment and connections between users can only occur if they are near each others. This who-is-near-who network is going to evolve every time users move and communication services such as the spread of any information will deeply rely on the mobility and on the characteristics of the underlying network. We will present here some results focusing on three key problems - measuring, describing and modeling evolving networks - using a typical evolving network where 41 sensors had been distributed to participants of a conference, which where asked to keep the sensor at all time. Each sensor was able to detect and record the presence of others sensors within their radio range which gives some information on the proximity of participants