I was on Indestructables not long ago. Guy game up with a pretty neat mod on the smaller moleskine notepads.

Requirements

pencil or stick pen to fit the length of the notepad.
Duct tape. preferably close to matching color of notepad.

Steps

Sharpen pencil to fit length spine of moleskine notepad. Or file off the extra body of the stick pen. Use glue to close off ink tube.

Pull 2 equal length strips of duct tape that measures same as moleskine spine. Rip one piece lengthwise in half. Place one of these half width strips length wise over the pencil with the sticky side facing away from the pencil. Discard other half strip.

Place pencil length wise along spine, the excess tape will lay flat along the front and back of the notepad.

Place second (full sized) piece of duct tape over the first, sticky side down, slick side up. This will stick to the first piece and have extra on each side to attach to the notepad.

The piece of tape facing the pencil will be slick, as will the piece on the outside. You can now slide the pencil in and out of the pocket it created along the spine.