Not sure which forum this should go in sorry but it's only a quick question...

Travelling from the UK to Vancouver, then the following day onto Alaska, after 5 days we go back to Vancouver for a week and finally down to seattle by train for 2 days before getting our flight back to the UK...

My question is, is there anything I should ask for or say at the border as we're entering and leaving the USA/Canada twice in a short space of time? Apparently there's something the USA can give you that you keep for your journey I've been told?

Just want to keep everything as speedy as possible? We have ESTAs already sorted of course, I've been to the USA on this ESTA twice now, getting my moneys worth