British Telephone Directories and Mail and Street Directories on the Internet: plucked from the web by Sylvia Milne, a retired librarian

Directories
Telephone, mail and street

European White and Yellow Pages
192.com
118118.com: free directory enquiries
Friends Reunited: trace your old school and college friends
Infobel : international directory
Lookup UK
Nethouseprices: UK House Prices: free information from Land Registry and Registers of Scotland
OnOneMap: find houses for sale with their asking price
Rightmove: properties for sale and to rent
UK Electoral Roll: there is a small charge to use this service

Iammoving.com: The UK's free online change of address service.
Malicious Letters and Telephone Calls: how to deal with them
MPS: Mailing Preference Service: eliminate unwanted mail: enables any member of the public to have their name deleted from or added to a mailing list.
Postal Information: rates, codes, stamps, international postal authorities
Postwatch: the watchdog for postal services in the UK
Royal Mail: includes Postcodes Online: print your postage online

BT (British Telecom) online telephone directory
BT (British Telecom): services for personal customers
Embassy World International Telephone Directories and country codes
Facsimile Preference Service: stop unwanted faxes
Independent Committee for the Supervision of Standards of Telephone Information Service (ICSTIS): an independent watchdog which supervises premium rate telephone information and entertainment services
Say No to 0870: offers consumers a cheaper alternative to most 0870 numbers.
Telephone Preference Service: register for stopping unwanted telephone sales calls
UKPhonebook: based on BT directory but includes area maps
World telephone directories on the web