I've discovered that almost everything you find in Skyrim has a function.
Yes, even paper roll, charcoal, ruined book, broom, etc.

Also, I've discovered, as you probably have found out too, that you can occasionally borrow horses. If you activate a horse that just says 'Ride' instead of 'Steal' and you ride it for a while, it will be in the neighbourhood every time you fast travel in the wilds (like a shrine, a village, a cave,...)
It's great! I found my first horse like that near Winterhold near the coast. It was a beautiful horse with spots and it followed me everywhere in the wilds when I fast travelled. You can mount it as many times you like and after you have dismounted it, it will simply walk away until you fast travel again.
If your borrowed horse dies, you can always borrow another one if you get another occasion.

Any other cool discoveries?