Matthew in Seattle simplifies family pizza outings this way:
My two-year-old daughter Iris loves pizza, and we often take her out to the local pizza place, but until recently she wasn't adept enough with her teeth to eat bites off a slice. She preferred her slice cut into little bites. Doing this with a plastic knife and fork (which is likely all you'll find at the pizza place) will drive you crazy. Solution: Toss a pair of kitchen scissors into the diaper bag. It's a snap [Actually, it's a snip. -- Ed.] to cut bites of any size with them, and you can wash the scissors when you get home.