TelephonyManager tManager = (TelephonyManager)myActivity.getSystemService(Context.TELEPHONY_SERVICE);
String uid = tManager.getDeviceId();
getSystemService is a method from the Activity class. getDeviceID() will return the MDN or MEID of the device depending on which radio the phone uses (GSM or CDMA).
Each device MUST return a unique value here (assuming it’s a phone). This should work for any Android device with a sim slot or CDMA radio. You’re on your own with that Android powered microwave 😉