The US keyboard is essentially the same than UK. $, £, , @ and some other symbols may be in different places - e.g. £ = alt 3. You can choose either to keep the US layout, or if you like more the UK, just switch it from sys preferences (I assume you remember layout in memory). I'd say 95 % of everything else is the same. All letters etc are on the same places.
The power plug looks different. Apples (incl. ipods too) work anywhere, 100 - 240 V, so you don't need a converter. If you have a spare cord, use that, or buy a small adapter - e.g. those adapters that work anywhere (plug any kind of plug in, and choose whether you need UK, Europe, US, Australia, South America output) - those are really cool especially if you travel, and e.g. British Airways and Air France sell them in the planes (during flights), about 10 £ / 15 seems a lot for one adapter, but that is all you ever will need anywhere. I am right now using that thing on my US Powerbook for UK outlets .. and change it to Europe thingy for the other room in this house.
A few more things:
1) Sales tax. Depending on city and state, it is in major cities often about 10 %. It is never in hte price when you see the price in the store, so that will be added when you buy it. So 2000 $ comes about 2200 $.
You can claim it back, I think, if you have the PB in original package and with receipts when you leave country - but if the customs spot you that way in UK they likely add the import tax (5%) and VAT (17%). I assume you don't want to throw the PB packaging away at airport. Maybe ground ship it to you if you want to have it later.
You can save the sales tax while in US. If you buy in mail order or in internet, from a store that does NOT have a physical store in that state where you are when ordering. So you can be anywhere but in NY to order from
www.jandr.com (as an example, they exist in NYC). In case you'd be in NY, you could always stay in a hotel in New Jersey and order it there.
Apple Store online adds the sales tax to any place. I would guess if you don't have the time (It could be shipped for next day) or don't want the hassle with that, just get it from the local Apple Store (feels so much better to get it from the real place, doesn't it?).
3) dvd region. It is not set, so the first time you insert a movie dvd with a region code, it asks if you want to set it = no problem.
4) warranty. This is a big thing. If you intend to keep the laptop for over 12 months, get Apple Care. US customers get 12 months of warranty - EU customers pay more for Apples but they get 24. So I think you want to et Apple Care with it.
I'd have the computer with me when coming back - if you have put your stuff in it already, how can they tell you did or didn't have it already when you went to US? (The worst case scenario, they noticing the power plug, "I forgot mine home so I had to buy a new one there" or similar). Just have the PB package shipped to your home empty if you like it (it is a pretty package, and you might like to have it if you later sell the laptop).
Where and when do you plan to get the PB? I am hearing so many Brits are wanting / thinking about Apple Shopping now that $ £ have a good balance for Brits.
