Is it possible to purchase an iPad in the US, to take back and use in the UK

Question

Is it possible to purchase an iPad in the US, and take back home to UK for use? I'm not sure if I would have to insert a UK sim into it, or if it would work as is.

Answer 1

In relation to the new Ipad with retina display Wi-Fi + Cellular version
After doing some research and speaking with various apple customer care representatives here in the UK the following is what I could find:
UK will be getting the A1460 model Ipad sold in the US (different mains adaptor).
Part number for the Ipad: MD522B/A
I also found the following IPAD A1460 models on the web from a website which seems to be written with Japanese characters
http://www.speedbusiness.net/shop/products/list_314.html
■Apple iPad with RD 16GB MD525xx/A
■Apple iPad with RD 16GB  MD522xx/A
■Apple iPad with RD 32GB MD526xx/A
■Apple iPad with RD 32GB MD523xx/A
■Apple iPad with RD 64GB MD527xx/A
■Apple iPad with RD 64GB MD524xx/A
So you can see that the part number MD522B/A given to me by Apple UK tallies up with A1460 16GB cellular version.
Since you can use Ipad internationally with a local sim of the local country then Ipad A1460 bought from the US will work just fine in the UK. At the moment A1460 in the US is the Verizon/Sprint version if you don't know the model number. (So to clarify It is not locked to Sprint/Verizon (contrary to what I have been told by all the apple reps I spoke to here in the UK - Apple should at least train/inform their reps to say the right things)).
If you want data connection in the UK just get a sim card for Ipad from
EE for 4g LTE connection
or
T-mobile, Vodafone, 3, and etc for 3G+ connection. 
The warranty is only relevant if the Ipad bough inthe US is different to what is sold in the UK. But from what I could find the parts are the same, i.e. screen, cover, battery, camera, etc. So if anything goes wrong you can go to Apple UK and they should fix it for you under warranty.
If you can get away with not paying customs charges then for example 32GB Wi-Fi + Cellular version comes to about about £490 ($720 + lets say 8.5% sales tax if bought in LA  and dividing the total by 1.589 conversion rate between $ and £ ). That is around £89 cheaper than the £579 for the same model sold in the UK.
Customs limit for importing without customs charge of a single item is £135 and it seems £390 collectively as pointed above. So anything above that in theory you should declare. But obviously that is not practical and customs don't question many of the items. So add up the shoes, jeans, and that digital camera you bought and do the maths.