It can show you arrows on where to turn by only when returning home to your starting location.
I've used it for driving around in foreign countries...you simply plot out where you want to go in advance, and pop it into the Garmin. It'll show you a bread crumb but no streets but that also means you're not purchasing new maps.
It's also how I explore new routes.
Not quite true. It will show you left/right/straight/summit/valley and several other markers, but only if you apply them to the course ahead of time. I routinely download new rides from Motionbased, import them into Garmin Training Center as courses, apply turn/summit markers, and upload them to the GPS. When following a course, it will display the distance to the next marker on the course.