More input from Wiki s Contributors:
If you are goning to Mexico or Canada you need a passport.
No. All you need is your passport.
Yes you do.
Yes, you now must possess a valid passport when traveling to either country.
A Passport.
No, you don't need a visa for traveling to Canada if you have a Dutch passport.
You need a passport to cross from America to Canada. While inside Canada, you don't need your passport, except for ID purposes.
Yes.
Yes, they also need a passport.
Yes and yes, unless you are traveling by road; on such case, you only need a birth certificate or ID.
It depends on how you are traveling and when/where you are going. If you are traveling by air or sea, you will need a passport to get back into the US or Canada effective as of 01 Jan, 2007. You do not need a visa unless you want to work legally.
Yes