Creative! I like the idea of reading the hiker's thoughts to figure out where they are, makes it feel more real.
Like other have said, it's way too easy as it is (I ran into a bug where the helicopter "found the hiker" even though it was nowhere near it on the map), but I think the concept has merit. I'd like to see how it plays with a bigger map, some more landmarks, a variety of searching units each with their own specialty (like helicopters are fast but can't see through the tree cover, so you'd use it to rule out large open areas or something).