Calling Home and Cell Phone Rental
The biggest two telephone companies are BT and Mercury. The minimum charge at phone boxes is 10 pence (50 pence for credit card call). Phonecards are also available in most newsagents and corner shops.
To make an international call, dial 00 then full country/area codes and phone number. In the UK, calls cost more during 8am-6pm weekdays. All 0800 numbers are free, and 0890 numbers charge 49 pence per minutes daytime (e.g., a call to the US Embassy's visa/cir/information line could easily cost you £10). When calling from hotel, check the rates before making a call.
There are a number of walk-in telecomm outlets that offer international calls at greatly reduced rates.
Cell phones are the best communication medium for most UK visitors. Your home wireless network providers may have roaming agreement with UK providers but roaming rates are typically high. If you have a GSM dual mode or tri-mode phone, you can buy a local UK SIM card (costs about $15) and top up some minites (about 15c-30c a minute). Most of the SIM cards for visitors charge the same (or less) rate for internalional calls. You could also rent a cell phone at airports.