Buying Laptop from US?

For Uni I'm looking at getting a laptop , specifically a Tablet PC. They aren't in great supply in Canada, and there's much more selection and better prices in the states.

Does anybody have any experience/knowledge with warranties for laptops bought in the US and moved to Canada? I looked at Toshiba and know they have an international warranty, so I think if I buy a Toshiba from the US the warranty still works here. Does anybody know of any more possibilites? I'm hoping for more options than Toshibas.

Any comments appreciated, Thanks.