Android :: Evenly Distribute Buttons Across Width Of Linear Layout

I have a linear layout (oriented horizontally) that contains 3 buttons. I want the 3 buttons to have a fixed width and be evenly distributed across the width of the linear layout.I can manage this by setting the gravity of the linear layout to center and then adjusting the padding of the buttons, but this works for a fixed width and won't work for changing devices or orientations.
<Linear Layout android:id="@+id/LinearLayout01"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:gravity="center">
Button
android:id="@+id/btnOne"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:width="120dip"></Button><Button
android:id="@+id/btnTwo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:width="120dip"></Button>Button
android:id="@+id/btnThree"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:width="120dip"></Button></Linear Layout>