iPhone Apps I recommend: #1
I live in Spain. I don't yet have data on my iPhone in Spain. Sometimes I drive around Spain and want a quality low-cost GPS/Navigation app for my phone that doesn't require live Internet connection.
I've tried a few options and settled on GPS Navigation 2 as the best of the bunch. It is cheap, it has offline mode, it works well, and you can buy data on a country-by-country basis. Or on a continent-by-continent basis.