For a few years, now, I have used a cheap FON wifi access point to provide limited (internet only) access for any visitors, separate from my own wifi access.
By default, a FON device offers two networks – one private and one public. In my case the private network is POSHGAMES, which my friends use; the public FON network is one that *anybody* can log into if they have FON credentials. The good part is that by hosting FON access, you yourself gain free access to any other FON point in Europe, which also includes many BT access points.
Living in a residential area, I think I have had about 3 strangers log into my FON access in the whole time I have operated it, but it has been worth operating it for the free access I gain when I travel.
And then there is today. Something is up, and my internet is completely down. But there are two BT-WiFi points within reach, so at least I have a basic connection until I can sort out what is wrong.
For anyone thinking “so, why do you need an internet connection at all?”; the FON network detects my FON’s presence on the internet automatically; and if it were to disappear for a week, I would find my roaming access curtailed. So you need to keep a device connected to be able to use the network for free. Also, most FON users (myself included) throttle the FON connection to about 1-2 Mbps – enough for email and basic surfing, but little else