I've just found out that a place called FON ships out free wifi routers in an attempt to create an open WiFi community. The idea is that you install their free (offer until 24.12.2006 or the first 15000 that apply) wifi router and connect it to your broadband connection at home. In return the wifi access point is open for use by other Fonero's (that's what FON calls their users). FON has created a map of access points using google maps which shows the coverage in a neat way.
With wifi in every laptop and soon probably in every mobile phone too this is definitely an interesting development - I signed up immediately !