The cheapest way to use the buses and the underground (what we call ‘the Tube’) is to buy an Oyster Card. Just go to any bus or tube station and ask, and someone will explain where to go, how it works and what to do. More details here if you want them.
Cabs. This gets complicated!
We have what we call black cabs (most are black, but they can actually come in all sorts of colours). These are the only ones that are legally allowed to tout for passing trade on the street (meaning you just see one, stick out your hand or attract attention, and they come to you). The drivers have to pass a test called The Knowledge of London, which is hard and usually takes about 3 years. But it means they know where everywhere is, and the quickest way to get there. These cabs are insanely expensive. Do not use them if at all possible.
We also have what we call mini-cabs. These are normal guys with normal cars who will provide a taxi service. They are not legally allowed to tout for passing trade. Legally, you have to book them at a minicab office. In practice, this just means a guy standing in a doorway with a clipboard. Identified by a flashing yellow light over the door way. There are literally hundreds of these, all over London. These guys are not licensed and haven’t passed ‘the knowledge’. However, they will get you where you want to go, and they are massively cheaper than the black cabs. Always agree the fare before you get into the car!
We also have guys who just cruise around in the evening, hanging outside popular tourist spots, asking if you want a ride anywhere. These are not licensed, and they aren’t even associated with a minicab firm. They are just scumbags (usually) trying to earn some easy money. Avoid these people and tell them to get lost. There are many stories of people, especially women, who take these ‘cabs’ because they are cheap, then end up being driven somewhere and assaulted or having their possessions stolen. Do not have anything to do with them.
Never take a cab or a taxi to get to or from a London airport. You will pay a fortune. There are good public transport alternatives, involving buses or underground services, that are faster and way, way less of a ripoff.
Cell phones. Good advice from InkBlot. Be aware that Britain has probably the highest charges for Telco services of any country in the world. ‘Roaming’ is always expensive, but roaming charges plus UK charges equals losing a fortune. Either follow Inkblot’s advice or you could even try doing without a cell phone for a while. It is possible!
Food. Rule one: never eat in a hotel or in a restaurant that is under hotel management. You will be ripped off and pay a fortune. Rule two: be prepared to be shocked how much you get charged in cafes and restaurants for even simple things like coffee. Welcome to Ripoff Britain.
The smart move is to do what Londoners do: go to a store or a supermarket, buy food you can either take back and prepare yourself, or ready-to-eat stuff like sandwiches and ready made salads. Much cheaper, but generally of very good quality. Places likes Marks & Spencer, Sainsbury and Tesco have good selections of ready-to-eat food at good prices, and they are everywhere.
If you want to eat out at a restaurant in the evening, avoid anything that looks or smells like a tourist trap, and forget official guides like Zagat’s. Go out of the city centre if you can. Find a small neighbourhood curry house or Italian place, and you’ll have good food and good service at a reasonable price. Be aware that adding alcohol to any meal in the UK always adds a lot to the bill. Make do with water if you can.
Also be aware that Indian food may not have a very high reputation in the US (so I’m told), but over here it’s considered wonderful and more or less essential to the London experience. Tasty, satisfying, generally of very good quality and always very inexpensive. And they’ll help you to order something you’ll like, if you’re not very familiar with an Indian menu!
This is a very cosmopolitan city, so you can find just about any kind of cuisine if you look for it: Indian, Chinese, Italian, Thai, Cambodian, Russian, French, Nepalese, Tapas, Japanese (sushi is big over here) and so on. But the smart move is always the same: go out of the city centre, explore smaller neighbourhoods, and find small, likeable places where you will get good value.