This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
By default, you can access your geolocation data and detect the orientation of your phone. Accessing the camera orcontacts, as you said, is only possible by using a tool such as Phonegap. But HTML5 provides also some nice features to compete with native apps like : offline caching/local storage