I’d just hate to see all that knowledge go to waste. Don’t get run over by a bus or anything, will you?
I was in London a couple of years ago, but was doing the super low-budget visit so I don’t know that much of my experience would be relevant. I can vouch for the youth hostel in Earl’s Court, but I take it you’re looking for slightly more upscale accomodations. 
I was in England in the first place for a study tour, and we flew British Airways. It was quite nice, much nicer than any of the times I’ve flown internationally on an American airline.
I don’t think I ever spent more than 7-9 pounds on a meal, and usually kept it under 5 pounds. Again, I was skimping, but you can certainly get sandwiches, fish and chips, or ethnic food at reasonable prices. Most hotels will provide a big English breakfast.
Speaking of food, I don’t usually recommend restaurants but there is one I always suggest for people going to London. It’s the Konaki Greek Restaurant at 5 Coptic Street, right near the British Museum.
Oh, and as other have said, it’s best to get most of your spending money from your bank account at a cash machine in-country or just use a credit card. You’ll want to exchange a bit in advance so you’ll have it on hand when you arrive, but between the lousy exchange rate and the service fee it’s not worth changing a large amount this way.
Sir*, you interest me greatly. I will be in touch.
*Gender inferred from username. If incorrect, please accept a humble apology.
You are correct. E-mails on my profile, even though we talking 7 months away.
Now, which crawl do you want to do? Theres at least 4 good ones I know of…
If it doesn’t include the Prinny Lou we’ll be having words.
Doris,
As evidenced above, Garius’ pup guide will have the Prinny Lou in the center, with mist surrounding it a “here be dragons” on the edges…
He must go to at least one other, nearer home, surely. There must be some limit to how far a Doper will walk for beer.
If Pauly is organizing it, it will have to involve the Ship as well. That’s gonna be some crawl.
As an American living in London for over a year now (and over 3 in the UK), I can make a couple of recommendations:
First of all, good choices on places to visit. I would throw in a couple more, if you have the time - Henley on Thames is a gorgeous little village on the River Thames, and if you come during June they have the Henley Regatta there. Nothing quite so cool as the tiny little town of Henly filled to the absolute brim with rich toffs quaffing champagne, talking about their manor houses, getting drunk and falling in the river! Priceless!
Otherwise,
-
Don’t tip in pubs. Tip anywhere else you have table service (such as bars, nicer restaurants). Don’t tip anyone else. Tip 10%
-
Come in July or August if you want nice weather, but there will be loads of crowds. The weather in Sept / Oct is a little less predictable, but still generally nice. It rains a lot in Spring. There are tons of outdoor events all over London in late summer, so it’s a great time to go to concerts in the park and such. And great fun, too!
-
London is expensive, especially with the exchange rate from US dollars. But not prohibitive; clothes are quite expensive here, as well as any sort of electronics gear, but the food isn’t as bad as people have made out.
-
Most of the major museums / etc in London are free. And there are some fantastic ones, to be sure. I would HUGELY recommend the Tate Modern (fine art), the Victoria and Albert (interesting and eclectic combination of stuff) and the Natural History Museum. I would seriously book a half day for each one, with travel time from most places in London
-
Do try Harrods and Selfridge’s. The food court at Harrod’s is an amazing thing to behold, but beware the prices - it is certainly not cheap. If you’ve got money burning a hole in your pocket, Selfridges will definitely take care of that problem.
-
Fly to Heathrow, and fly on a European airline, if you possibly can. I like BA internationally, because they don’t treat you like cattle (or not as badly as the US airlines do), and really like Lufthansa. Virgin I have heard is fantastic, and if you can get something like Emirates GO FOR IT!
Heathrow is just so much easier to get to / from than Gatwick for Central London. You’ll waste any money you save flying into Gatwick on transfers to the city. -
If you’re travelling around London (or any major city) at night, you will have lots of dodgy characters slow down and ask if you want a minicab. This is an unlicensed cab. Risks are they aren’t insured, might not have legal drivers, and if you don’t negotiate the rate to where you’re going before you start off you’ll get hosed. But they can be cheaper (and easier to find!) than the Black Cabs. Black cabs are licensed, and you can hail them from the street.
Oh, and have loads of fun. Feel free to email me if you want some further tips as you get closer to the date.
Cheers!
Oh, and forget about the traveller’s checks and currency exchange - your visa will be accepted most everywhere, and you can use the ATMs here to pull money from a US bank. Do call your card company before you leave, though, and let them know you’ll be travelling, as at least once I forgot to do this and wound up with a dead card in a faraway land. Not very much fun 
I’d suggest more like a day for each (or two weeks, for the V&A)
Eh? The Gatwick and Heathrow Expresses are almost identical in price, and the regular trains from Gatwick cost only slightly more than the tube from Heathrow. Plus, Heathrow is a dump in many other ways. Plus, BA and Virgin are the only European airlines who are included in the Heathrow transatlantic cartel - Emirates operate out of Gatwick.
Gorillaman - you’re right on the V&A; i was thinking of something else when I posted that.
But I wasn’t just talking about the cost, but about the transportation and stuff.
For instance:
My place to Heathrow - 1 walk / bus of about 1/2 mile (£1.20), One tube ride to Hatton Cross - £2.20, One bus to Terminal 4, or just stay on the tube to T1-3.
Return is on the Piccadilly line again, which goes right into central London (almost called it downtown there :)) right along Hyde Park, Soho, Leicster Square, etc… I live in SW6, so it’s not like I am right in the middle of Red Ken Land.
To Gatwick:
Cab or Bus to Victoria, train to Gatwick (£20 last I checked for the Gatwick Express), and a hell of a lot more frustration. Return is even uglier… especially if you get to Victoria late at night as that is not the nicest area.
Plus, I just don’t like Gatwick very much. It’s way uglier and seedier than Heathrow in my opinion, and neither one will ever win a beauty prize!
And I was just pimping Emirates because their service is absolutely killer! I’ve never flown with them, but universally everyone that i know who has has loved it.
If you tend to get motion sick, don’t ride on the top deck of a double decker bus.
Or, a train direct from Kings Cross, Farringdon, Blackfriars, London Bridge, etc…or any of the thousands of options to get to East Croydon and change - OK, so it’s £8 and still more than the tube, but comparing the Gatwick Express to the Underground is hardly like-for-like!
(And I’m guessing you haven’t spent too much time in Heathrow Terminal 1, if you think Gatwick is seedier… )
Fair point on the trains; I guess it’s just a pain to get to Gatwick from SW6.
And yes, T1 is seedy, but I still think Gatwick is seedier.