Always keep in mind that the staff is taught to make your stay as pleasant as possible and fulfil most of your wishes. So it is often a matter of social engineering to reach your goal.
Many good hotels offer business centres.
Just use it when you check in - most places require you to have a credit card or won't let you use the phone or won't even let you in. Don't use a stolen card when you check in, or you won't have a safe sleep, fearing that they could come and get you. You would be safer if you tell them upon check in that you misplaces your card and don't need to make long distance calls, and just want to pay with it in the end. This doesn't work always, but sometimes. You also need a faked ID upon check in with the same name as the cardholder.