But most people I know rely entirely on wireless phones, which won't work during a power cut.
And I've always wondered, why? The phones have rechargeable batteries in them that last for several days on idle and many hours of talk. Why don't the base-stations also have rechargeable batteries as back-up? Maybe the battery uptime would be hours rather than days, but and awful lot better than zero.
I still have a non-wireless phone is a cupboard, so I can avoid being charged by BT for diagnosing that my phone line is OK but my base-station has died. I thought everyone did.