由美國去加拿大既問題..

應該可以, 美加市民往來是雙方向的, 我剛在六月持加拿大車牌由Toronto 經 Niagara falls 開車去 Buffalo 玩, 絕無問題, 但好似遲些會變, 詳情: http://www.goingtocanada.gc.ca/Going_To_Canada-en.htm
希望幫到你

I live in Upsate New York, maybe I can help with this question.

You can use your driver's license go to Canada by land in theory, even before the passport law, but a driver's license can not proof your nationality.

I have several friends (white) they were born in US, whenever they are going to Toronto, they bring their birth certificate with them. Your sister passed the citizenship test, she should has a certificate of US naturalization, please bring that with her to proof that she is a US citizen, it's better safe than sorry.

以前絕對可以,而家一樣可以.二零零八年一月一日後可能唔可以.
我話可能嘅原因係美國修改入境法.以前坐飛機由加拿大,Maxico同乘坐郵輪往加勒比海回美時無需護照.但今年8月1曰開始就要.陸路就98年1月1日.因為甘,碰上暑假.移民局就倒瀉籮蟹.原本四星期可取得passport.(俾多一倍錢可加快至兩星期)而家有人十二个星期都未攞到.出發時都未有護照.搞到羣情洶湧.所以而家剛發咗新嘅行政指令,只要能證明自己已申請護照.就可以用車牌入境.所以我話08年都可能未使.
以上講嘅係而家由飛機入境.你從陸路暫時可以沿舊例用車牌到零七年十二月三十一日.

由美國過境去加拿大即使自己開車都一定會經過海關，出入境都會查看証件。 尤其是美國最近改了例，規定加拿大人進入美國境一定要駛用護照, 這樣一來，加國海關亦相應嚴格了呢。

據我所知， 沒有美國護照就要申請一種叫"回美紙" 方可保障於出境後順利返回美國。 要問清楚才好起程，免得回去時被留難。