> Kidding aside, I think it'd be awesome to get cards like that -- and maybe the USPS thinks so too, which is maybe why they're letting them through. =)

haha, totally agree, I suspect that the canceled stamps are detected, probably automatically, but when a human gets involved, he thinks it's funny/cool/nostalgic ("why those are the same stamps my grandma used!"), and just laughs and passes them on...

Also, you know, Christmas... :]