Serial number from Samsung Device running Android

Question

I have a Samsung Galaxy Tab 2.0 (7\")

On the back of this device is a serial number of the format

RF3C6000MNA

When I go into settings on my device, a

Answer 1

public static String getManufacturerSerialNumber() {
  String serial = null; 
  try {
      Class c = Class.forName("android.os.SystemProperties");
      Method get = c.getMethod("get", String.class, String.class);
      serial = (String) get.invoke(c, "ril.serialnumber", "unknown");
  } catch (Exception ignored) {}
  return serial;
}

Edit: it's been a while since this answer, here's a couple of updated points:

• The OP asked about Galaxy Tab 2 and for that indeed the answer was ril.serialnumber (even for the non-3G model - see this gist). According to Himanshu's answer Galaxy Tab 3 uses sys.serialnumber (also backed by this answer). sys.serialnumber makes better sense for tablets as ril.* stands for Radio Interface Layer, something most tablets are not equipped with (ril.serialnumber, respectively, makes better sense for phones).
• There is no standard API for getting the device serial number (ie the serial number on the packaging - not to be confused with Settings.Secure.ANDROID_ID or the various other "unique" identifiers scattered throughout the API). This means it is up to the manufacturer to decide where to store the device serial (if at all). On the S3 Mini it's ril.serialnumber, on NexusOne it's ro.serialno (gist), on Galaxy Tab 2 it's ril.serialnumber, on Galaxy Tab 3/4 it's sys.serialnumber, on Lenovo Tab it's none of the above. These settings appear to be the usual suspects, when looking for the device serial, but shouldn't be taken for granted, and as such, shouldn't be relied on for tracking unique app installations.