Yes if your parent layout is a RelativeLayout you can position Views in relation to each other or to the parent here is a simple example (Warning didn't type this into IDE, may contain typo):
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<Button
android:id="@+id/mBtn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="I am a Button!"
android:layout_centerInParent="true" />
<TextView
android:id="@+id/mTxt"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:text"Some Text"
android:layout_above="@+id/mBtn" />
</RelativeLayout>
That will make your layout look roughly like this:
________________________
| |
| |
| Some Text |
| [I am a Button!] |
| |
| |
|______________________|