What I do before I head out is write an email to my wife. Said email can be forwarded to SAR (or printed and faxed).

In the email (in addition to the text), I include a link to Acme Mapper that shows my route in a fair amount of detail. For example, here is the route I took last Saturday.

One time when I came back a lot later than expected, my wife did call SAR. They got a hold of me on my cell once I got into range. I told them that everything was fine and that I was just running late. SAR sent a truck up to the trail head and had me check in with them on my way out just to be sure. One of the SAR guys thanked me for adding my map link. He said it makes it so much easier if they really know where to look.

Anyway, I think Acme Mapper is worth knowing about even for non survival purposes (multi-person trip planning for one).

HJ