The pizza is always great at Pizzeria Delfina. The restaurant's Neapolitan-style margherita pie is one of the best in the city; its wood-fired crust is as light as it is chewy; its side dishes highlight the best of the season in simple, satisfying ways. None of this is a secret, which is why there is almost always a wait at the restaurant's Mission location at 18th and Guerrero. But there's hope for people craving a thin-crust pie and a side of ethereal meatballs who don't want to show up and find a wait of an hour or more. Last fall, Delfina installed a webcam pointing live at its chalkboard waiting list. So now you can not only see if there are 20 hungry people who will get seated before you and decide to order delivery instead, but you can also put your name on the list and head elsewhere for a drink or two while keeping an eye on your progress.