We tip the standard 20% when we have pizza delivered, but normally just pick it up since its less than 1 mile from my house. When I pick it up, I don't tip, even though there is a tip jar on the counter.
For the first time ever this week, I tipped in a situation where I normally do not leave a tip. Its a local family type restaurant where the majority of patrons sit down and are waited on. However, they have a drive thru order board as well (like at a McDonalds). I ordered from the drive thru and then drove up to wait for my food. I watched as the server gathered my items and then included salad dressing, crackers, silverware, napkins, plates. She also cut a serving of coconut cream pie and placed it in a "to go" container. She then came to the window completed my transaction. The whole process took her 3-4 minutes. I sat in my car wondering if she was paid the server rate of $2.85 per hour or a higher rate for those in non tipped positions. I am guessing its the lower rate since I remember sitting in the same restaurant and watching regular servers who had tables also working the window. I didn't want to ask her so I decided to tip her 20%.