I am planning to visit Vancouver, BC end of this month and wondering if I have to return my I-94 while crossing the border as my stay in canada is going to be 3 days and I'll be back to US after that. I have been to canada via rainbow bridge, Niagara Falls few times and never gave my I-94 as all my visitis were less than a week. I am not sure if this is the same case on the seattle-vancouver border crossing. Can someone please throw some thoughts or their experiences?. I am on H1 and I-94 valid until Sep 2010. Also can I rent a car in Seattle using US DL and drive in canada? Thanks in advance for your answers.