I have found that phone cards that have no per-call connect surcharge (fka operator assistance charge) from a home phone and no expiration date have been the best value.

All phone cards have a per call surcharge of so many minutes when used from a pay phone or a Charge-a-Call (tm) phone.

Some states have in-state long distance calls costing more than out of state long distance calls.

Sometimes a pay phone in the lobby costs less overall compared with a hotel room phone. You have to call their respective operators and ask questions.

In many cities including Boston figuring out what is a local toll call and what is an unmeasured call and what is a tier one (or tier 2) local measured call requires referring to some cross reference tables in a phone book.

A few hotels have hall or lobby phones that make free local calls. Together with a phone card you can make not-too-expensive long distance calls here.