GPS and web based maps sure take the guesswork out of travel. It almost feels like cheating. But if I really thought it was cheating I wouldn't use it. It means you can arrive in a city you don't know and know where the bus terminal is, where your hotel is, where the main landmarks are. This makes you much less vulnerable to aggressive cab drivers or touts. On the downside it takes out some of the mystery of discovery. Then there's always the possibility of losing your phone.