Re: Need recommendations for London sightseeing
Just a note on money and traveling outside the US. Get your spending cash there, not in advance in the US. You'll spend less in transaction fees. You can also use a credit card almost everywhere, but there are fees for each use as well. In fact, best to bring cash, and exchange it there so you don't incur credit/debit card international fees. It's also smart to notify your credit card banks that you'll be traveling, so they know that any overseas use is authorized. I've been embarrassed in Canada a few times by forgetting to call ahead. (I've been embarrassed there for other reasons as well!)
Also, your US cell phone will cost a million bucks to use there. Either be very judicious with its use, get a calling card (read the fine print about connection fees!) use Skype to dial out (2.3¢/min) or simply plan to not make or receive any calls home.