You can log into the wifi of the University of Geneva under the profile «guest-unige» for free. Guests will be requested to enter their cellphone number to receive a wifi password. This password is valid for 6 months.
For more information: https://plone.unige.ch/distic/pub/reseau/wifi-guest-unige-english
Access to wifi is also possible through your personal Eduroam profile. More information under (in French only for the moment): https://plone.unige.ch/distic/pub/reseau/eduroam