2. Math. Regardless of wether you love or hate math, doing it with a pen sucks.
3. Journaling. When I sit down with my journal and relax I make mistakes that need erasing, plus when I am lost in thought the aroma of cedar is sometimes all it takes to bring that thought out and get it onto paper.
4. Self Defense. In a dark alley with an attacker I'd rather defend myself with a pencil than a pen. Easier to break part of it off in them with a pencil, talk about the ultimate splinter. I bet CSIs would love me.
5. Space Travel. My Fisher space pen is nice but for the same money I could have a box of platinum grade pencils. They'd add a nice natural smell to what I imagine would be a rather stinky cabin. Plus pencils weigh much less than a space pen.
6. Canoeing. I used to teach canoeing in Minnesota, if you have your map out and want to make notes, a pencil floats in the water and is biodegradable if you lose it. A metal pen will sink and a plastic pen will pollute, the right pencil will do neither.
7. The Glovebox. It does not matter how cold or how hot it is outside, a pencil will still write. Plus, wood has a lower heat capacity than plastic or metal so you won't burn your hand on a pencil (ever grab hot bread out of an oven?) like you would on a pen.
8. Bowling. See golf.
9. Being Eccentric. About the only pen that makes people ask about your writing instrument, is a fountain pen or a quill. When I pull even the most common of pencils from my pocket, especially if I get my sharpener out too, people notice. Sharpening the point of a pencil gives me a moment to think before I speak.
10. Collecting. Everybody remembers that you are the guy who collects pencils. Pencils are, in my opinion, the only truly ubiquitous technology the world has ever known. They are everywhere, are useful to all generations and you find them in the gift shops of most tourist traps and airports for about a buck.
11. Taking Notes for Class. See golf.
12. Marking Textbooks. You can mark it up all you want and sell them back when you are done (as long as you erase).
13. Drawing. You can use your finger to blend, shade and lighten pencil lines. Pencils are a joy to draw with.
14. Playing Card Games. See golf.
15. To Do Lists. Instead of checking it off, try erasing it for closure.