Air:
Getting to London by air from the U.S. almost always means flying into either Heathrow or Gatwick International Airports. Some airlines fly into London City, but you're less likely to find any convenient flights there that are cheaper than those arriving at the major airports. By the way, these airports aren't located right in the middle of the city, so you'll be forced to catch the train/tube to get to London proper. As stated, this city is a major international gateway. It's next to impossible to not find a flight to London from your nearest major airport.

There are many ways to find good airfare. You can read more about my tips on good deals if you follow the "General travel tips" link to the left. Below I've listed some sample fares from a few different cities for different times of the year, just so you can get an idea of sample prices.

These prices represent the lowest basic fares, including taxes, taken from a sampling of major U.S. airlines. They represent round trip travel leaving from and arriving back in each U.S. city on a Tuesday.

Please note that these are not the best fares you can find, by far. I wouldn't fly from Seattle to London in February for more than $400 R/T. Had Jason and I not flown on the weekend, we could have made it to London for $375 from Seattle. Remember that airlines charge more if you fly Fri-Mon, as opposed to the middle of the week.

Don't forget to check into alternatives when planning your itinerary. It may be cheaper flying out of Canada, or flying into Manchester rather than London.

Rail:
Like many European countries, the U.K. has an excellent rail system. Though renting a car may be a better option in some cases (e.g.- if you're looking to visit out of the way attractions, such as Stone Henge), rail travel remains the easiest, most convenient, and potentially cheapest way of getting around the U.K.

The British rail system is pretty well organized, and it's relatively easy to figure out where and when you need to be to catch the next train. For some reason, there has been a rash of delays along some of the British rail lines in recent months. We experienced this first-hand going from London to Manchester, when we arrived two hours late (possibly due to the snowfall from the evening before).

Britrail passes work the same as Eurail passes on the continent (Eurail passes are not valid in the U.K... weak sauce). Just make sure you write in the date on your pass before you get on board! Keep an eye out for occasional deals on rail passes. We bought our passes in time to take advantage of a 25% discount, and this was before the foot and mouth outbreak killed British tourism.

London has 8 major train stations, all of which connect to different areas of Britain. Make sure you know which station in London will be your point of arrival or departure. Euston station was our destination when we arrived from Manchester. Keep in mind how many people commute to London. If you're worried you may be caught in the business commute, consider making a seat reservation ahead of time. The same goes for traveling by rail to football matches. The morning of the Arsenal-Man U game, there was only one car on the train to Manchester that didn't have seats reserved. We were among the few lucky fans who didn't have to stand the whole trip north.