I'm trying to find the best known methods for distinguishing a tablet from a phone.
We recently discovered that a Tablet device (Thundersoft Bamboo) was getting a phone version of an App in the Google Play store instead of an alternate version more suited for tablets. After contacting the ISV we learned that the reason was that they distinguish a phone from a tablet based on screen properties. Specifically for the Bamboo:
getResources().getConfiguration().screenLayout = Configuration.SCREENLAYOUT_SIZE_NORMAL