we got some for the PSP and the DS and they both work fine on the UK PSP and DS - same as if you order them from Amazon.com, this can sometimes be cheaper than UK and you get them earlier!!!
If you buy an xbox360 or PS3 in the US you will need to buy a step down convertor in order to power it from a UK mains supply when you get back. I think you can get one of these for £30-£40 so it's still possible to grab a bargain if you want to
As both are home entertainment consoles and not portable devices the manufacters (Microsoft/Sony) have included region encoding in the design of the hardware, but ultimately it is up to the games developers to decide whether or not they include this within their games. This means that you probably wont just be able to walk into your local games store and buy the latest titles if you have bought your console in the US, at least without doing some research first.
That's good news on the PSP games.........I'm getting one for Xmas!!
I was assuming I'd be ok to take it on the plane with me...is that right? Also, I was wondering if it's possible to buy any kind of adaption which allows 2 sets of headphones at a time?
Yea, you can buy headphone splitters which allow you to use 2 pairs of headphones at once. I think they're universal so you use them for any type of dvd/mp3/psp etc. I've seen them on internet stores but you can get them in places like Dixons probs.