I don't think you need to fuss with region codes or any such. You'll need to change the timezone and that's about it.
Since you've posted to slashdot asking whether you should bring your laptop, and used the word 'geek' 3-4 times, er yeah you probably are the type that would go into withdrawl without your laptop. It's a bit of a hassle to drag it around but you'll probably want it. If you have something lightweight like a netbook you'll definitely want it. Get a UK power adapter (AAA or pretty much any electronics store).
A laptop is useful for three things while you're traveling: a) planning/researching/arranging tourist stuff, b) uploading photos, c) satisfying your internet/email/gamer addictions.
Most hotels will have internet service for some fee. Your call on whether it is worth the money. You might be able to get free wifi from cafe/pub places but don't count on it.
The British museum will hold your interest for a day. If you're in London for two weeks, you can probably hit all the major tourist attractions. Get any tourist guide and work your way through it. Once you learn the Tube you can pretty much get anywhere you want. Make sure to go to a play or musical or two even if that's not normally what you're into. Go to at least one castle and one cathedral too. For geek cred, go to the Eye of London and try to think of as many movies as you can that had a scene showing that in it.