I have, and it sucks.
Around here, it's simple to find your way out... follow gravity: Go down. Go down. Go down. (Follow the canyons)
Eventually, you'll hit a road, highway, camp, pipeline, river, stream, cabin, mining claim... something. If there's still no sign of help, follow the water or keep going down.
Florida wasn't so kind. Getting lost in the swamp is a terrible feeling. At the time, it was made much worse by the fact that I was driving and couldn't go back via the "road" I came in on, and the sun was going down...
That time, I got lucky, and found a 'jeep trail' intersection I recognized on my topo map.