Just to finish this topic, I am flying Detroit to Orlando and crossing in Sarnia by car. If you think logically, customs will be at the border in Sarnia - there will be no customs at the Northwest Terminal since I am flying domestic from Detroit to Orlando thus noone will be wanting to challenge my citizenship. Northwest said they require photo proof of identification and this is all to check in. Now 2008 is a different story. I think we will all need them then so better plan early if we are travelling next year!