There are several possibilities. Surely you can store the configuration in the EEPROM from where your sketch will read it at startup. But you'll need a way to store it there if you're moving to a new location. You have a lot of possibilities, a keypad with LCD, using the USB connection, using a serial connection, using a Bluetooth connection and so on. It really depends on what hardware you have connected to your Arduino or what kind of user interaction you have in mind.