Avoid the long lines and sit down quickly with these tips at Zingerman's Deli.
Go to the bread counter in the deli. After you taste the samples, get a bagel. Ask them to slice it. (Or ask for one of their yummy bialys which I did last time I was there.)
Proceed to the deli counter or the fish counter, if you're hungry for same. Ask for something you'd like to put on that bagel.
Go ahead to the head of the line! You don't need to wait for the long lines at the sandwich ordering counter. If you want something to drink, you can get it at checkout. Assemble the sandwich yourself when you get to your seat.
Interested in a more substantial sandwich? You can get premade sandwiches that are delicious (but smaller than the big Zingerman's sandwiches) at Zingerman's Next Door.
Call ahead! You can phone in your order ahead of time and have it ready when you get there.
It's not really a secret menu, but it does let you walk in, grab something delicious, and go sit down and take in the scene. It also lets you get through the line in only a few minutes.