The standard pay scale for drivers is an hourly wage plus $X for every pizza delivered. Pizza places frequently add a delivery charge for houses that are further away from the restaurant based on the assumption that the delivery guy has to burn more gas and time to get there. Time is money to a delivery driver. A long drive means missing the chance at other deliveries. The downside is that sometimes the shop takes the delivery charge instead of letting the driver have it.
Moving to the specific delivery, realize that it's very likely that the first time the driver ever heard of you and your pizza was 7 and a half minutes ago when his manager gave him an 22-minute pizza and reminded him of the 30-minute guarantee. There are dozens of reasons your pizza might be late that have nothing to do with the driver. Maybe the shop is crazy-busy, maybe he got caught in traffic, maybe the person who took the phone order got the address wrong and he had to call for a correction and updated directions. The delivery guy is the public face of the shop and gets all the abuse for any mistake. He also gets to deal with people trying to scam him with bogus complaints, fake coupons, physical threats, and the classic: delay the driver at the door while your friends steal the other pizzas from his car. (I'm looking at you, Sigma Alpha Epsilon at Oregon State).
If your home is difficult to find or there's some hassle that's due to your situation, tip extra. 20 years ago when I was delivering pizza, a dollar was a pretty standard tip. A pizza runs about $20 here in San Jose, so I start with $3 as the base and adjust up or down based on time, hassle and attitude.
When calculating the tip, consider the driver's perspective. Is your home particularly difficult to find? Does your house have numbers prominently displayed? Did you put the porch light on? Did he have to ring the bell three times and wait around for five minutes while you looked for your checkbook and that coupon you're sure is around here somewhere? Finally, realize that if you're a regular you will be remembered. Being known for even adequate tips helps insure good service in the future.
-=Logan
Research, facts, a Republican needs not these things.