You can create a Rovio account and store your scores and progress online. This allows you to access them by signing in to your account even if you delete and re-install the game.
Our friends at Angry Birds' Nest have also written a comprehensive tutorial for backing up your progress on various platforms. The guide also shows you how to move your progress from one device to another, as long as the two devices are running on a similar operating system. You can read the complete guide here.