It’s obvious enough that “old-fashioned” guidebooks won’t help if you’re trying to pack light. No matter what your destination is, there are about a million travel iPhone apps out there for you to choose from, but we prefer Wallpaper’s City Guides. Why? For starters, we prefer to cut down on costs by not depleting our data allowance while abroad. These guides are all packed in there, so you don’t need a 3G network to access the info. And it’s only $3.99, which is less than you’d spend on any book.