carry out pizza, no. carry out food place where they have a dedicated person who is tasked with watching for my food, packaging it up, grabbing utencils, etc then most definitely yes, i will tip them 10% or round up to $2 which ever is more.
last night i grabbed carry out from pf changs. the girl there makes the same amount per hour as the wait staff and relies on tips to make up the difference between the $2/hr (or whatever wait/bartenders make). this is the way it is at most restaurants.
the rewards for treating your bartenders and wait staff well are incredible.