An extra benefit in addition to the alphabetical listings, are the advertisements on the pages, adding information on the lives of our ancestors.
The collection now includes some 280 million historic names, addresses and numbers from across Britain, and was done in association with BT. Ancestry.uk says there is nearly full coverage for England as well as substantial records for Scotland, Ireland and Wales.
Why are phone books so useful for family history research? While a census was made only once a decade, the phone books were updated every one or two years, providing a record of a family's movements between the official census records. While the most recent UK census accessible today is 1901 (1911 won't be released until 2012), the books go through 1984.
From these listings, researchers can understand their ancestors's lives a bit better. Telephones were initially only available to commercial enterprises or to those who could afford the new-fangled invention. As costs came down and a wider segment of society had them installed, researchers can now track more contemporary family movements.
This is another great resource for researchers. My search turned up historic information on my Talalay cousins who moved from Mogilev, Belarus to Moscow to Berlin to the UK, and then to the US and Canada.
There, in the November 1939 book, was J (Joseph) A (Anselm) Talalay, at 28 Eton Place, Haverstock Hill, NW 3, phone number PRImrose 5353. In this case, while not critical information, the entry does provide data that I wouldn't have been able to easily access. There were 12 listings, 1938-1983, for three family members.
These numbers will also become useful when time machines become another tool in the genealogical arsenal. Researchers will be able to go back in time and phone their ancestors to meet them at the machine!
From Reuters, here's a peek at "Yellowing pages offer a glimpse of phone history."
LONDON (Reuters) - The old home phone numbers of former Prime Minister Harold Macmillan, composer Edward Elgar and poet John Betjeman are among millions being made available online for the first time on Wednesday.
Genealogy Web site Ancestry.co.uk has spent three years transferring nearly 2,000 old phone books to the Internet to help people research their family tree.
From the first slimline directory of 1880 that contained just 248 names to the heavyweight volumes of the 1980s, the collection traces the inexorable spread of the phone network.
While callers today would struggle to find Tony Blair's private number, anyone who owned a copy of a 1930s directory could reach former prime minister Ramsay MacDonald in Scotland.
His home address is listed with the old-style word and number combination, "Lossiemouth 3089".
In the 1941 directory for Tunbridge Wells, next to the listing for the Mac chain of fishmongers, there is an entry for "Macmillan, Harold; Pooks Cottage, Birch Grove. Chelwood Gate 81". He went on to serve as prime minister from 1957 to 1963.
Famous figures from the arts were also listed.
Read more here.