In a foreign country where you know nothing and nobody, you have two options: carry around a gigantic Frommer's guide and look like a toolish tourist or download Triposo to your phone and look like a slick local.
Best part about Triposo is that it's free. The devs culled seven sources -- WIkipedia, Wikitravel, World66, Openstreetmap, etc -- via an algorithm to create guides for 50 different destinations on Android (30 on iOS). You can use the app to see what's worth sightseeing, where to go out, where to eat and more. There's even tidbits of landmarks and major sights (thank you Wikipedia!) and the app, which comes with a map of the city, works offline too. Free. [Android Market, iTunes via TechCrunch]