This may be different in other countries, but in Peru, they say "con permiso" or just "permiso" when you are trying to get around another person, like on the sidewalk or in a mall. They use "perdon" for a simple "I'm sorry". For example when you bump into someone on accident. They also use "disculpe" when they want to get your attention. In English, we just say "excuse me" for all three.