My Favorite Analog Productivity Tools

I'm often asked about my favorite productivity tools, and while I do cycle through an array of apps and digital tools, my absolute must-have in the office is my set of hourglasses, seen here. These particular hourglasses come from CB2, but any will do: the larger one is an hour, while the smaller one is 15 minutes. I use these hourglasses to measure out specific activities in my workday in an unobtrusive, soothing fashion. The 6-minute hourglass reminds me to get up, walk around and focus on mid-to-long-distance objects and keeps my longer breaks on track. The smaller hourglass helps me measure out Pomodoro cycles, email-checking periods, short breaks, and quick brainstorming sessions.

What productivity tools do you use? Do you prefer analog or digital solutions?