Oslo Central Station (Oslo sentralstasjon or simply Oslo Sentral/Oslo S in Norwegian) in the lovely Norwegian capital offers WiFi through The Cloud. That isn’t free, though.
There is however free WiFi at a cafeteria called La Baguette. No password required. The WiFi network is also called LaBaguette, and you can access it by simply sitting close to the cafe or ordering one of their reasonably priced coffees while you read up on, say, Dag Solstad on your laptop. Gratis WiFi til alle!